I said it before and I’ll say it again, Lemmy’s (and Mastodon’s) issue is that the users experience is influenced by the defederation.

The server side needs to be a decentralized database stored on a bunch of servers with all content available from one website with an API so people can develop apps for it, but otherwise the decentralization should have zero impact on what content the users have access to. In other words, do like Reddit but instead of having a ton of servers owned by AWS hosting everything, have those servers be owned by anyone who wants to host part of the database.