You gotta embrace it.

Federated space is not like reddit in that there is no single domain.

But it is like reddit in that there can be multiple communities covering the same topics within the fediverse, with different moderators, rules, subculture, and focus.

A perfect example from reddit is r/knives and r/knifeclub. They're the same thing, often with the same users, and very similar rules. But the vibe has always been different. Discussions go a different way nerdiest because the users aren't exactly the same. Both are wonderful.

Look at it like this, using another knife example because that's a hobby of mine. Bladeforums exists. Allaboutpocketknives exists. They're both knife forums. One existing does not mean the other isn't useful (though you might find arguments about either one lol). Neither of those takes away from r/knives existing. None of those invalidates YouTube knife channels (though most of those are crap tbh).

You'll also find that none of those places does anything significant in the way of connecting to each other.

That is where the fediverse shines. Everything here is inherently connected once discovered. There's places to find communities that have already been created. If you go to the "all" tab within your home instance, chances are that you'll run across them by accident in a similar way to reddit's r/all.

So, there's no need to connect communities on different instances by default. If /c/s decide to do so, that's awesome, but it's no more necessary then subreddits having a "similar subs" section in their sidebar.