@FloralBunting
Well, I'm a cosplayer, but only because that's what the hobby is called. I'm not under any illusions that I'm doing anything other than indulging a niche interest...
Yes, it is now, it wasn't always however.
In my mind the change in terms came around the same time as the change in attitude or focus, but maybe that's not really the case. When fans became fandoms, maybe, or enthusiasts became something else? It's not really the enthusiasm that has changed, but something else. It seems related to all of these very detailed, extended universes of various kinds, be they Star Wars or Marvel or Harry Potter.
Mind you, they area also much more popular now, where it was quite niche stuff at one time - my local comiccon is unrecognisable in many ways - and less homemade, more corporate.
But I am thinking in terms of these HP fans who seem so invested, even as adults, and it's similar in other fandoms. I know a heck of a lot of people my age that were into those hobbies as teens, and some still are, but it's not the same as these groups.