It's ok to be bored with the game after a long time, just take a break, play something else and then come back if and when you feel like it.

But the gear grind part is very confusing, except for fractals you could still be meta with exotic berserker gear from 2012 in some builds. The game could improve in many areas but gear grind doesn't seem one of them.

Yeah, you need to spend some gold for BiS but usually even that doesn't require any kind of group activity or grind. At most some ls currency farm if you don't have any spares

Outside of legendary (which is purely looks and convenience) I don't see any big farm or grind required