About the "less fragmented" part.

I don't see how that is possible in the fediverse.

Let's say I like fishing and a fishing community exists in five instances... That fragmentation you can't avoid... In the other hand it helps with the resilient part I guess. The more fragmented it is the harder it will be to take a community down.

Having multiple communities under the same subject in different instances will soon become normal, for better or for worse.

I have read some comments in github discussing possible ways to develop something akin to "mutireddits" (or more recently custom feeds) so people can group communities like this across different instances.

Let's see how all this plays out. Interesting times ahead in the fediverse.