The problem with this reasoning is that many of the popular communities are actually on lemmy.ml, and they’re not so easy to replace. I mean, in terms of content and engagement lemmy is already a pretty small place as it is.
I think this is a core problem of lemmy as it is right now. This place is meant to be federated and decentralized. Instead it is heavily centralized as communities lie on one instance. What one needs should be federated communities as well. Like say c/[email protected] is the same as c/[email protected]. this way one could subscribe to communities on your home instance and if the home instance defederates from one other instance the community can defederate from the community on that instance without completely breaking apart