I wonder if this accounts for why different people have different outcomes with this stuff. Like a lot of people in this thread, I've grown up with violent movies, violent video games, violent rap music, and so on. I don't think it's had a major effect on me. The reason why I say that is because I get upset when I see clips of people actually being killed, like the ones we all saw from the Rittenhouse shootings, just to pick one example. So it's not like I've been desensitized to violence to any extreme degree.
On the other hand, I also grew up in an environment where there was no real-life violence. Every once in a while, a couple of guys would meet up after school for a fist-fight or something. Otherwise, it was a whole lot of nothing. No violence of any kind in the home, no violence of any kind in my neighborhood, no violence of any kind anywhere near where I worked as a kid, and only trivial schoolyard-type pushing and shoving at school. The violence that I consumed in the media has always been kind of a cartoon that exists in some alternate reality, not my reality. Maybe it's different for people with different youth experiences.