@Neon Shoji
Mastodon needs a structure where the accounts are handled at a central hub

I strongly disagree with you there. Other than that it's not needed (there's no such thing for e-mail and that has worked fairly well for decades), it's not going to fly. How are you going to make all admins in the world, individuals, enterprises, governments and whatnot, submit their account info to one central hub? I know I'm not going to.

You could use something like OpenID to make account handling easier for your users, but a central hub of control is exactly what the Fediverse is not.