It’s not that users want to centralize everything. It’s Lemmy’s design that promotes it, because despite federation, there are still advantages to choosing big instances and communities.
Joining the largest instance makes searching, joining, or opening communities much more seamless.This can be addressed by:
Improving the search so that it can find communities, or even content, that no one on the instance has subscribed yet.
Making it easier to open a community in your home instance.
In addition to Sub/Local/All feed, you can have a “moderated” feed (with communities selected by admins). The “local” feed is most useful for instances on a specific topic. But for very small instances, it’ll be too empty at least at first. So a moderated feed can create an on-topic feed that’s more lively.
For most topics, only the largest communities are large enough to have good content, so everyone wants to join them. To address this, you need some easy mechanism to subscribe to all communities on a topic. For example, we can let communities follow other communities. Then people can create topical meta-communities that aggregate content without centralizing it.
It’s not that users want to centralize everything. It’s Lemmy’s design that promotes it, because despite federation, there are still advantages to choosing big instances and communities.