Your username in the fediverse is not honorfaz, but @honorfaz@kbin.social, just as an email. It's the same for communities (or sublemmy, or whatever we decide to call it). It's not c/something, but c/something@instance.com. This is why everyone still has a unique handle, but no unique admin.
I'm on my own instance for example, running in my living room, and yet here we are, talking. Internet as it was intented.