They aren’t hipsters. There aren’t enough hipsters out there for Phoenix Comicon to have 77,000 attendees. These are fans, regular fans.
And as you point out. Fandom has been around for a long time, the hipsters wouldn’t get to be first.
Nobody in America reads. We’re in the post literary culture.
Music festivals routinely sell out to audiences before a single band has been announced to people who’ve largely only ever heard a few of the bigger names on the bill.
The herd mentality pays off in numbers. It’s “trending”.
The comic book artists (like Neal Adams, Jim Steranko, and writer/editors/fans like Roy Thomas) are ignored by 90% of the “fan” attendees. They plain don’t know who these people are.
At the Stan Lee “panels” the talk is 95% about the casting choices of the latest Marvel movie/tv show (which Stan is not even the deciding vote on).