

It's interesting how much of pt1's praise and fandom is rooted in reading into the subtext and sympathizing with and understanding Denji, while much of the hatred and dismissal of pt2 is from rejecting the subtext and refusing to sympathize with or understand Denji-
-while retroactively mischaracterizing pt1 dennis and claiming pt2 is flanderization
Obligatory mention that pt2 is flawed (though we probably disagree on what those flaws are), and this is not a "defense" of the ending (i think it does matter but we can argue later)
Denji struggles to maintain happiness without being Chainsaw man, and Chainsaw mans existence brings hell. The usual rebuttal to Pochita's "...only find heaven when you're in hell" claim is any panel with Denji looking content or happy, hanging around Aki, Power, Reze, or Asa but that surface level observation is ignoring the fact that just being with them isn't (inherently) at odds with his dreams or wanting to be Chainsaw man.
The tragedy is, if he was told to stop being Chainsaw man to be with them (before his "I want to be chainsaw man...!" moment at the end) he could've probably attempted to move past needing Chainsaw man; Unfortunately with everyone wanting his heart, and his own desires, this likely wouldn't've lasted.
He is forced to be Chainsaw man due to his circumstances, getting to chase his dreams of sex and fame, and the thrill of violence ultimately outweighs any notion of family- even one with Nayuta- or properly confronting his guilt.
"I would probably be depressed for a bit, but after three days or so i'd probably be back to enjoying my life"
"And if they die too! I'll find another new family!" Tough luck bad guys! I Can make a perpetual motion machine!"
"...Which side is heavier"
"Somebody like me shouldn't be allowed to be happy!!"
Denji's entire life is built on unfair circumstances, and having to pick between two choices is just another facet of that. This is a deliberate writing choice, there is no "correct" answer.
These bad circumstances lead to bad choices and bad outcomes, whether this makes Denji a 'bad' person or not is really up to your own ability to sympathize with him, even at his lowest and most selfish moments.
But for better or worse he'll pick a third option, he'll always get back up, even in the face of guilt or loss he can always fall back on the high of chasing his dream of having tons of sex while he gets to carve up bad guys. The only way for someone in Denji's shoes to move past this, was to have never had it at all. This is not a moral to be taught or a nihilistic world view, this is a story about a character.
(or fujimoto couldve just decided hed get better because thats whats supposed to happen to the hero at the end duh)
I can understand Denji not being able to grow is frustrating (and the release schedule didn't help) but that's what the entirety of part 2 was telling us- even with his moments of clarity, guilt, maturity, or suffering and at the end of the world, he couldn't break from his vices- but even if he could it would probably be too late.
obviously its fine if you dont like it and "it being the point doesnt automatically make it good" but disliking Sisyphus for rolling his boulder or disliking a tragedy for being tragic isnt really a "valid criticism" i dont think
thanks for reading maybe