It’s far more complicated than email, at least I can send an email to any valid address from any other address by default ( mostly ) - Lemmy / Fediverse is like needing multiple email addresses that each one can only email some of the others, and you might not even get the response someone sent you unless the content is literally carried back to you.

I have multiple accounts on multiple instances, and sometimes I come across posts I read with one account, but my comments or the responses to those comments just aren’t there, so you only get a portion of what is out there.

It’s kinda a terrible experience in that way.