>>32876360Pokemon has gotten stale. The last HUGE meta change was gen 4 with the split.
It hasn't really evolved since then. That's why they have been using novelty gimmicks like Mega Evos and recently Z-moves to "keep it fresh"
Still, it was gen 3 the game that brought more innovation to the franchise. There isn't much they can do anymore, given this is franchise for children, and games shouldn't be too hard or complex for them.