If you are a fan of pokemon and want actually challenging games with stories that vary in quality, fan games and ROM hacks are your go-to.
My personal recommendations right now are Pokemon Vanguard and Unbreakable Ties, both phenomenal fan games despite not even being completed yet. You'll get well over something like 20-30 hours alone with Unbreakable Ties and it's just in its 4th beta. Both feel like passion projects in the best way possible and Unbreakable Ties is looking to be a master craft in the art department as well (minus a few fullscreen art scenes that pop up).
At most, you'll have to join a discord server, as annoying as it is, if you want more up to date info on the game and download links.