for me personally the downfall began with gen 5 (pseudo reboot . don't like most of the artwork of the mons itself)
gen 6 was cool but XY were really short and felt like you need only 5 hours to complete the whole game (on a sidenote: I don't like megas)
ORAS was cool but was missing key features from emerald
about gen 7: i played like 2 or 3 hours and couldn't force myself to play more (and don't like this super duper ultra mega awesome special moves)
as for gen 8: don't have a switch and I dont like the idea of gigamax thing, if there's an emulator that I can run I will give it a shot
but I'm realistic I think I grew out of this franchise it was fun and I have some of my best memories with pokemon but I think my journey is over (atleast for now)