I'm 41. Kpop isn't my thing at all, but then again, any pop isn't my thing and has never been, so age has nothing to do with it. I've been into rock since my teens, and into international rock (US, Scandinavian, Jrock, anything) for a good 10 years.
I've been into Animes since I'm a pre-teen, never stopped loving it.
I've been into Mangas since my 20's, never stopped loving it.
I've been into Asian dramas only recently, and not ready to stop.
I'm certain I would have been "into" many things if they had been readily available earlier. No way would I have been able to read mangas 30 years ago for example, as they just weren't being exported! The internet has allowed lots of international culture to be spread around the world and made people discover new, interesting things. I think this young generation is very lucky for that.
I also do believe that the Asian wave that's flooding the world right now with kpop/dramas etc...to be aimed at younger audiences, but anyone with an open mind could fall hard for it too! It's just harder when you're older to share your passion with your friends because most of them have no idea what you're on about, or aren't interested. So I find myself talking and sharing the stuff with my 13 year-old son lol. At least, I'm less lonely, but he's too young to enjoy dramas yet, so it's just animes for now.
Also, when you're older, you tend to prefer dramas where the cast isn't too young: they need to be at least in their mid 20's for me to be interested: not that younger actors are bad, they're just harder for me to relate to.
Your own tastes will change as you get older: you may end up not liking so much the stuff you love now and turning towards shows you would never have considered before for example. You'll probably become more critical too, and your tastes less broad lol.