Let's get some things out of the way first.
The below text is an interpretation only, I am not an expert neither in interpreting media, nor in psychology, nor in cultural context of given media. I'm just a random asshole on the internet, and an amateur at that. I also use profanity and am mature enough to talk about human sexuality without much shame, so if that's not something you're fine with, you can close this page now and go read something more sanitized.
Second, shounen is, as a rule, shit: it follows the predictable formula of "protagonist is too weak to deal with shit, protagonist tries real hard, protagonist gets better", rinse and repeat for thousands of episodes consisting flashy fights, chibi-style emotes, occasional fanservice shots of boobs and crotches and superficial moral conflict, until it gets to the absurdity levels best intentionally illustrated by One Punch Man and is the anime equivalent of Twilight series or such.
There are exceptions to this rule, either because you've watched them when you were at the target age, or they're created, written and directed by people suffering mental ilness and would rather channel that into barely pubescent children piloting giant mechas to defend humanity against existential threats (I am happy though that Hideaki finally either got therapy or proper medication, judging from EOE 3), people who seem to have true talent like Watanabe-san or are so over-the-top that by itself it subverts the genre, either intentionally or not; not that it really matters. I'm looking at you, JoJo.
Chainsaw Man is none of these things. Reminiscent of Bleach in more ways than one, it follows ... frankly, it doesn't really matter, even though the pilot episode pulls at your emotional strings rather efficiently, the worldbuilding is commendable or the characters are pretty cool. I've seen that before. It is the other aspects that are more interesting for me, and how the creators of the show (or manga that I didn't read) expose the psychological paradigms any first-year student of psychology should be aware of. I also think that might be intentional.
I'll start with the obvious.
It's not a pyramid, it's a hierarchy, god damn it. And the hierarchy is not rigid, as it depends on individual, circumstances and peoples' actions are usually driven by more than one need.
Oh and you don't have to cover the lower hierarchies fully in order to have needs in the upper hierarchies, but i'm getting ahead of myself.
When we first meet Denji, our protagonist, we basically have an animal: his most basic needs are not met and have not been met for such a long time he only has a vague outline of the higher-hierarchy needs, expressed as "having a girlfriend". Denji is absolutely unaware that other needs higher in the hierarchy exist, because his goal is to "get a toast with jam", i.e. his most basic physiological needs are not met.
It is interesting though, that some of his needs higher in the hierarchy is met. His pet devil Pochita at least partially satisfies the need for friendship, connection and family. The events in the pilot of the series also mean that Denji gets to back the basic needs level when Makita picks him up. At that point his interest in her is on the most basic need level, and later on crystallizes as "the need to touch boobs".
The need to touch boobs and have sex is probably typical of most shounen media, either covertly or overtly, but in this particular case it ties very neatly into the hierarchy of needs, especially with other characters, with needs in the upper hierarchy (mostly seeking self-actualisation in form of revenge, for example) looking down on the fulfillment of lower-hierarchy needs, with Denji avidly (and rightly) defending the validity of such needs.
His character at this point is mirrored by Power, who is a complete sociopath. She is also stuck in the lowest portions of the hierarchy of needs. But unlike Denji, she doesn't seem to progress.
The progression upwards in Denjis' hierarchy of needs is demonstrated by the disappointment(s) he experiences after touching Powers' breasts and subsequent distinction between act of reproduction and intimacy facilitated by Makima; in the later scene following Denjis' first kiss (damn, that is not what I expected it to be) his refusal to have sex also shows that he is becoming more aware of his higher hierarchy needs.
There are also Freudian angles in the series, and I believe it's intentional.
I mean just look at the image and try to seriously claim that in that sexually charged scene this is not a Freudian reference, and sometimes a cigar is just a cigar and of course scissors usually lay down open next to your documents when you're just stamping them with your Hanko. Considering these are official documents, that's not a simple Hanko too, it's a jitsu-in, a "true seal", your most private key certifying your identity. Losing your Hanko, especially a jitsu-in is kind of a big deal in Japan, as you can only have one. In other words, that's a fucking penis right there ladies and gentlemen and I refuse to believe otherwise.
So obviously, there's an angle here. It does seem that Makima is a mother character to Denji (she literally brings him into this particular world after deciding if he lives or not), and his intention, obviously, is to... In words of The Doors/Jim Morrison: "Mother, I want to – aughaughaaarrhhhh". Denji is living the Freudian dream, folks: both of his father figures are dead, and one of them he's killed himself. We'll see if any of father figures appear in season two, but meanwhile the position is vacant. It doesn't help that Makima actively encourages his Oedipal complex; however the image above is a very obvious reference to the subconscious male fear of castration as an outcome of this travesty.
Thankfully this is not the only part of the series that can be interpreted through Freudian prism, because that would be boring. You know what other, less cocaine-fueled and penis-centered, theories Freud had? Yes, the internal mechanisms of the psyche: Id, Ego and Superego.
Okay so let's refresh that.
So we have this sea consisting of depths of unconscious we can't look into it, but otherwordly creatures beyond our reach and understanding exist there, there's preconscious where it's dark, but with some effort and perhaps a good searchlight we can find things and bring them out into our daily mumbling of conscious life where we try to pretend there's nothing beside it.
In that sea floats an iceberg that's us, consisting of three parts again (see, gaben, people like number 3) - Id, completely submerged in the darkness, Ego and Superego extending into the tip of the iceberg. These are all essential for a human being and each one has a very important function in the psyche. Id hosts all of our drives, desires and impulses, it is also the only part that has actual psychic (as in psyche - soul, not as in telekinesis bullshit) energy. If we'd give Id complete control, it'd probably be a disaster. We would eat, fuck and kill without any furhter thought and the world as we know would be over in whatever time the nukes need to fly whenever they need to fly. Id keeps bothering Ego from below to do just that and promises to provide all the psychic energy needed to do that. Why exactly Ego doesn't just submit to Ids' wishes, I will get back to in a moment. Ego is "me" in a nutshell, all that's going through the first persons' mind; it's a bubble of "self". Now why Ego is not simply YOLOing and getting crazy is because it's being kept in check by Superego, who is keeping the castration scissors handy, figuratively speaking, in case Id and Ego step out of the line. It's scary in that aspect, but ultimately overextending its' powers and getting what Superego wants would detrimental to the host of the three entities as all of Ids needs would be denied and we would die of starvation, so Ego does this balancing act between the two.
This ties in neatly with the world of chainsaw man: devils are Id manifest, driven by primal needs and desires. They are also necessary for humans' survival as they provide the power so sorely needed by them. Devil hunters primarily represent Superego who wish to exterminates devils indiscriminately. Ego... well it's obvious, it's the protagonist of the shounen the young male audience would be identifying with, caught between a rock and a hard place.
The characters above are a good illustration of traits associated with the three major mechanisms of the psyche.
Power is a representation of mostly Id - just look at her claiming food for herself, immediately grabbing apples as soon as she gets hungry and general sociopathic behaviour and her willing to side with whoever's winning - i.e. whoever can satisfy her needs best.
Aki is definitely a superego - he's overseeing the two literally under his supervision, telling them to be more polite, to behave more appropriately. As superego, he's also essentially powerless and since Id/devils are the source of power in chainsaw man universe are his mortal enemy, using that power directly is deadly to him; he's forced to employ the power of others, mostly via Ego to attain his goals.
Denji is the balancing act - he needs a Superego to survive, but his heart is a devil which gives him all of the power; he is successfully balancing between killing devils and being one.
I don't think I've noticed anything else that's standing out as obvious from Freudian perspective; there are hints of Jungian theory too, like devils being creatures that emerge from the collective conciousness (i.e. common psychic gestalt, in terms on how humans see the world, not the telepathy bullshit), and that Makima actively hides her devil part and that can be interpreted as her Shadow (something that ego denies existence of as it doesn't fit the ideal perception of self, i.e. something that needs to be hidden away real good), but it's, you know, not something that can stand on its' own legs at this time of the series.
As I've mentioned previously, I personally think at least some of these things are intentional, and while it's true that almost anything involving humans can be subject to such analysis, especially where Freud's concerned, it's just too obvious and easy.
On the other hand, it is shounen, so maybe it's just meant to be stupid, obvious and easy.
Until next time, friends. And remember, sometimes a cigar is just a cigar.