There's no fundamental problem with federation. The UX can be made good enough for the average user.
The problem here is the developers. Federation developers don't seem to be interested in UX. They aren't focusing on adding the polish and ease-of-use users expect out of a social media platform.
90% of the issues with Lemmy isn't because of federation. It's because of basic UX:
- Error messages silently discarded everywhere. Stuff "loads forever" when in reality some error has happened and the operation has already failed.
- Links to other instances are not handled properly (WTF? Links to other instances are a huge part of federation, how could you not handle this properly?)
- To follow a community in another instance, you have to search the community? TWICE! (The first search loads the community asynchronously in the background). WTF?
- They decided to rewrite the entire UI using websockets causing bugs everywhere? WTF? Over-engineering at its finest. At least they are trying to undo the rewrite currently...
- Searching for communities should search through all communities that the instance is federated with. It should feel like there's only one instance. Right now search shows only cached communities. WTF? Are we expecting users to understand caches?
I'm hoping that the influx of new developers (who are more UX focused) is enough to polish the platform for end-user use by June 30th. It's going to be difficult, but it's possible.