Pokémon used to be my favorite franchise by far, but not anymore. However, unlike you with Zelda, I still like the new Pokémon games and I've played every mainline game since Platinum (I'll probably skip Ultra Sun and Moon though). I just don't like them as much anymore as I used to, and there are other games now that I like better.
I think I'm just growing out of it, the games are becoming too easy and simplistic for me. They seem to have lost some of their magic.