Since I'm technically a Zoomer due to my age, I can answer you from my perspective.
The true answer to this question is simple,
COVID LOCKDOWN
When the Covid lockdown happened,
various social media sites and
Discord spiked in popularity and forced people to be chronically online since there wasn't any other way of communicating. While it is true that groups like these existed way before that
(see: /222/ crew, a shitposting group turned "ironic" pedos") I 100% believe that COVID had completely destroyed people's brains and allowed many younger people to be sucked into those groups, this could also explain why this kind of shit started popping up so massively after the lockdown. Reading
@Azumanga's testimony from the OP, it seems like he suffered a similar fate, a young impressionable teen who got sucked into the wrong crowd, but he's still a massive faggot who endorsed a
pedophile and decided to proudly say that he's one of them when confronted meaning he's completely unwilling to change and is only upset because he got doxxed