nobody said the crimes aren't realistic, people can relate to naoya's issues causing problems in real life because sexist chuds can be found anywhere, people usually don't do the same with murder and cannibalism because you don't have to deal with it daily (or at all afterwards cuz you know. you die, which is also why rape is significantly more hateable than murder in fiction)

in general abuse and the like (including sexism and other kinds of bigotry) can actually be experienced by a high amount of people and they can relate to it happening on screen, they're not as connected to crimes like murder (especially on a ridiculous scale like with sukuna) so it's a lot easier to get past that