I just ran into the same thing in a video I was watching, non pony related, but the same as in, the video maker thought it was some genius new thing on the internet when I remember the same thing existing back in the 90s.
I think too, that newer generations don't understand how it used to be before the internet was so easy to access and everything you could ever want to find was on it. Nerdy stuff has always been around (and mainly seen as a bad thing). They were having conventions with cosplay in the 60s. And it certainly wasn't something that was widely accepted like it is today. Like, take gaming culture. I don't like the term 'gamer' because it denotes a certain type of person, but I've been gaming my entire life. Back then it was seen as a nerdy thing (nerd stuff was bad) and something you did by yourself in a dark room because you were a loser with no friends
I mean, I'm glad it has become so mainstream and people are are enjoying it together, but growing up it was definitely seen as something an outcast kid did, not the norm.