Earlier quoted context omitted.
This works with email, but not so much with Fediverse. There is no standard or - AFAIK - even attempts domain/account sharing (unless you hack your way around), you'll have to be you@mastodon.your.name and you@lemmy.your.name and you@peertube.your.name, but not [at least not easily] you@your.name if you want to use it with multiple systems.
I had absolutely no issues with hosting my own mastodon, I pay $7 dollars a month for a VPS with backups. I'm the only user that can register on my instance so it's just me. I'm `@aj@s.aj.immo` and I can follow and have conversations with other mastodon users of various servers seamlessly. I was just doing it this evening in a thread while tagging four different people on four different servers. When people tag me in…
Just Mastodon - it's not what I'm talking about. Please let me know if my parent comment wasn't clear enough.
Mastodon certainly works and you can be just @aj (as long as no one else with the same host-local part walks in, I guess) no matter where the actual conversation is hosted. But what about Lemmy, Peertube, or other Fediverse systems? I'm aware that Mastodon can talk to them with some success, but AFAIK it is only optimized to present certain types of content, so if you want Reddit-like user experience rather than Twitter-like one you want Lenny. And then you need a different subdomain. And then you realize you're splitting your identity on the same network in two - and in my opinion that's an indicator that something is wrong.