>>509291622 (OP)There's probably a lot of reasons, but I think a big part of it is that there isn't any real cultural zeitgeist to rebel against. The Internet has allowed people to split their hobbies off into little micro-communities with extremely similar interests. For example, you can have two dudes who do absolutely nothing but watch YouTube in their free time, but have absolutely no overlap in the shit they're watching. Everyone is into their own highly specific stuff with maybe a few friends who share the particular interest. People have less in common, which is ironic because we're more homogenous in the way we speak and think than ever before.
Irony culture and pervasive conflict avoidance is also a factor. You can go up to a guy wearing a Dead Kennedys t-shirt, rightfully call him a poser faggot, and at worst he'll probably just cry about it on twitter. Same kind of dude might've stabbed you in the late 90's. Nobody's really invested in anything because they're terrified of being judged and hide their interest behind ironic self-effacement, when they choose to express it at all. Hard to rebel against that kind of attitude.
Finally, no one's shocked by anything anymore. We've seen it all, again because of the internet. You could go out tomorrow in pink spandex with your skin painted bright green and people would just assume you were doing a Tiktok challenge or something. Hard to take pleasure in being a rebel when nobody gives a shit about your rebellion in any way, shape, or form.