The upside of communities is that each can moderate themselves, and you can block the ones that don't moderate to your standards.

Yes and no, ideally we would also still have communities. You can imagine how a topic like Henry Kissinger's death could be talked about in both of a politics sub, and noncredibledefence esque military based sub.

The point is basically to give better search functionality and bridge these communities by topic in a way.

you can see one in the other.

Right now, you can't see Mastodon toots unless they go out of their way to link a Lemmy community. I hope we'll get better integration at some point (a way to subscribe to users or hashtags, maybe), because that would give a lot more activity