Besides politics it's mostly technology, and humour. That's basically because only a very specific kind of person has chosen to be on Lemmy, at this point.
Here's a couple at random that are humour:
!antiquememesroadshow@lemmy.world
!reallyshittycopper@lemmy.world
And here's a couple that are something else:
You'll notice it's mostly .world, because that's by far the biggest instance, and also not very political.