Because let’s say you’re Tom Hanks. And you get TomHanks@Lemmy.World
Well, what’s stopping someone else from adopting TomHanks@Lemm.ee?
And some platforms minimize the text size of platform, or hide it entirely. So you just might see TomHanks, and think it’s him. But it’s actually a 7 year old Chinese boy with a broken leg in Arizona.
Because anyone can grab the same name, on a different platform.
This would require some kind of federation alliance of instances that check each other’s usernames to ensure no duplicates over the whole network. Sure, maybe lemmy.shit doesn’t recognize the network, but then they don’t get federated with.
This is definitely possible, but it doesn’t seem to be happening.
Oh I’ve been thinking it needs an official alliance now for some time. Where a preagreed set of protocols are all adheard to. Just so all the services can play nicely with each other. Still decentralized in operation, but unified in experience.
And if some rouge instance wants to stay seperate, well, good luck growing hexbear.