Part of why I dragged my feet on ever checking out JJK was the reputation I heard was that it's a BRUTAL grimdark story where ANYONE can DIE in a snap and the author says FUCK you. And after finally catching up with the anime that just... Isn't the tone at all?? Like, Game of Thrones, Gantz, Attack on Titan, etc other cornerstone grimdark reference points, I think one of their defining hallmarks is not just that characters die suddenly and violently, but that human life is nasty, brutish, and meaningless, and it's your own fault for being stupid enough to get attached.
Jujutsu Kaisen on the other hand, I don't know how you can look at one of the most recent casualties circa S2Ep20 of the anime where that character gets a full entire episode reminiscing about their childhood, and the moments and people that meant most to them, and come away thinking the author's intent was to treat life as meaningless. The amount of screen time devoted to the following character who gets badly maimed, the audience gets enthusiastically shoved neck deep into their insane kaleidoscopic passion that is never once undercut or subverted. Both of these characters, far from being callously snuffed out and dumped in the trash, were shown immense love. What we got was not a statement of their life being disposable, but a celebration of life, a reminder of who they are, what they cared about, what made them special, who they loved and who loved them and will remember them in turn.
This is a story about curses born of misery, hatred, and malice. It is also a story deeply concerned with dualism, especially when it comes to attachment and desire. Misery stems from worldly attachments, but it is not weak or foolish to become attached to things in this world. To love something is to set yourself up for the pain or anger of losing it, or sadness of having it denied. But that love is what makes life worth living anyway, and what makes it worth it to keep fighting. We as the audience are sad because we are attached to these characters who have met terrible fates. We see enough of them to be able to clearly picture the whole rich life they could have lived surrounded by friends and feel the sting of that path cut short. It is a story about how it was worthwhile knowing them well enough to be attached anyway, even if it meant unavoidable heartbreak.
This is true of both the human protagonists as well as the curses! Volcano Man and Mahito are ruthless killers who cruelly take lives without a thought. They also have hopes and dreams that they earnestly try to protect and follow through on, and face heartbreaking despair upon defeat. They feel pain just like we do, but must nevertheless be killed. Humans face pain through the very act of living, but nevertheless must live.
In true grimdark fiction there is rarely anything good in life for characters to return to once the battle is over. In Jujutsu Kaisen, on the contrary, there is enough good in life that we see it even amidst the battle. I can see that no other way than an expression of genuine affection. Truly bleak fiction leaves me wondering why everyone involved doesn't just put a gun in their mouth and be done with it. JJK provides an answer--because you'll get to laugh about ruining an expensive shirt, because you'll meet an acquaintance's hot mom, because the next human earthworm movie is coming out, because your favorite idol is doing a meet and greet this weekend, because maybe someday you'll finally go to Malaysia. There are many answers, and none of them are stupid.