Pick a specific goal before you log back in - whether that's completing the Pokedex equivalent, building a base setup you like, or pushing through the endgame - because without one the grind can feel samey fast. I came back a few months ago after a similar gap and found myself just doing dailies in circles until I remembered why I'd stopped. Once I set sights on breeding a specific Pal with ideal stats, the whole thing clicked again.
The content additions are real, but honestly they're incremental rather than transformative. New Pals, better base building, raids, and breeding depth all help, but the core loop - catch, grind, build - is still fundamentally the same. If you bounced off that rhythm before, you'll probably hit the same wall unless something about your patience for it has changed.
That said, if you've got friends playing or want a chill multiplayer grind, it's definitely more fleshed out than early access. Just don't expect a different game. Jump in with a concrete target in mind and you'll get more mileage out of it.