Pathfinder_Kingmaker. I spent ages talking about builds and strategies on that reddit sub. I still miss guiding new players into the games. The BG3 community is the closest I’ve found but it doesn’t scratch quite the same itch due to 5e’s simplicity.

Pathfinder does have a few active communities but they are all for the tabletop. The one for the game on Lemmy.world is dead as a doornail.