i've been wondering about this myself, lemme vomit out some hypotheses.
zoomers came of age after the golden cambrian explosion of the internet. by the time they were able to experiment with their own content, all the fun low-hanging fruit had been taken.
in the 00s it was millennials on newgrounds making shitty mario sprite cartoons with him saying "fuck" and having his dick out because that was their our
version of rebellion. but it was stupid and they knew it, they were just experimenting with this "new media" thing and fucking around for fun. the paradigm was shifting every year and there was so much promise and potential on the internet that it seemed like there were no limits. that's why it was so fun to keep pushing the boundaries on violence and i dunno racism? things that were so obviously wrong that it was funny, and that you could never see on tv.
the zoomers have been raised in an internet establishment. there is no question of where the boundaries are, because they are now strictly constrained within the corporate structure of a few internet monoliths. they've already seen everything there is to see since they were small children. and they've already been made aware of the banality and insignificance of their existence in comparison to the billions of people before them. what else can they get off to anymore? how else are they supposed to feel but depressed?
i kinda think of it like spicy food. they were raised by the edgiest shit on the internet, which is like being raised by uber spicy food. they're already de-sensitized, so they need even spicier shit. the spice here is irony, they need more layers. those layers can be weirdness, esotericism, and anti-corporate behavior of defacing recognizable brands to appeal to each others' common depression (even though corporations have attempted to reverse course and glom onto the depression meme anyway).
thanks for reading my dissertation i'm probably wrong