There is nothing stopping the fediverse from checking with other instances to see if a name is already in use. That would be a pretty cool feature to avoid a whole bunch of duplication.
Yup, this is just as easy
If you notice one of the "[email protected]" communities is always posting edgy bullshit, you unsub and go on your way. No different than unsubing from "Actual" or "True" variants on reddit.
Wait, he's got a point though: Why not something like this:
A user wants to create a new community. He enters a name, then the system checks and informs that "the fediverse already has a community by that name +here and +here." The user may still create this same community on this instance - or he might say, hey cool thanks, and go subscribe to (one of?) the existing ones instead.
This would only help if people creating these communities were not aware that communities with the same name exist on other instances.
Even if this feature did discourage someone from creating a new community, some other fief lord would be along shortly to create it.
I did feel the same way about multiple communities initially, but now I've been here a while I realise that it's just not a problem - just subscribe to all of them, that's the solution.
This is the same thing as having a community on Discord, Reddit, Twitter, and Facebook, except you get the feature of them seamlessly working together.
I mean, this is how everything worked already. People start subreddits and have to get traction, make their way to /r/all, etc. Having ~one single space~ wasn't magic, and things work exactly the same.
If you see a community that interests you, subscribe to it and be the change.