A big part of that is on the design side. We really need the ability to fork/ clone/ merge/ migrate communities across instances. Lemmy was designed to be an “entire” reddit replacement. Because of this, we end up with redundant communities with less activity. Migration of accounts and communities could effectively solve this issue.

Its possibly lemmy could have been designed such that communities of similar type could be aggregated into a single instance. For example, maybe you start a “snowboarding” community on .world, but when a sports focused instance pops up, you might want to migrate your community. A few instances build like this.