As it stands now, you can download all of Wikipedia for offline viewing. It's not restricted in any way. And since Wikipedia is looking for objective truth, not opinions, I'm not sure what benefit federation would do. You want it centralized, not broken up. What happens when two instances decide that their version is the only correct one?
I just don't see any benefit. This feels like when everyone was slapping "blockchain" on things because it was the current buzzword. What is Wikipedia failing at currently that decentralizing it would make better?