Chainsaw man has an interesting premise, and an interesting start, but somehow the author managed to fuck it up completely. Feels like chainsaw man was made with no planning at all, and every chapter the mangaka just did whatever he wanted, there are no themes he tries to approach and no messages he tries to pass. There are almost no likeable characters and every plot point that has a minor chance of being interesting is absolutely fucked over. Absolutely terrible worldbuilding, almost nothing is explained and the mechanics of a lot of powers and creatures presented are left hanging. Because of the lack of world-building, a lot of plot points feel half- assed. If the worldbuilding was abandoned to focus on a better story/characters, it would be fine, but it's not. When the characters aren't generic they have absolutely shitty personalities or no personality at all. Makima, which is a really important character in the manga, and is apparently one of the characters the author put more effort in, is a mediocre character with a generic design and generic goals. Almost none of the scenes that were meant to be impactful were delivered, because I couldn't care about any of the characters involved. Also most of the comedy is also bad. Any trace of romance in this manga is poorly written especially when it involves the main character. Speaking of which, denji has an uninteresting personality, shitty goals, and is basically built to be relatable to any horny teenager that is too busy jerking off to think about anything happening around him. And my main problem with this manga is probably that horniness is apparently the only feeling the author wanted people to feel while reading this manga, at least every 5 chapters or so there has to be a scene with sexual content, as if it wasn't enough for the main character's motivation be entirely based around sexual stuff already. Boring fighting scenes with a lot of confusing panels, the manga's art is mediocre at most, and most of the character's designs are bland and boring. The thing this manga does a lot too is unnecessary gore scenes, which sometimes take entire pages and those get old really quickly. A bunch of interesting concepts for enemies, powers, and worldbuilding in general were completely wasted on this narrative disaster called Chainsaw Man.
If you are a horny and edgy teenager who likes nothing but violence and sex, you'll probably like this manga, but, if you stop to think about anything that happens, your enjoyment will be immediately ruined. Also, if you've already read any manga with at least decent fighting scenes, you'll probably find chainsaw man's fights boring too. Do not waste your time if you really want to read something good and don't be deceived by the anilist score. It is a poorly written manga.