XMPP

Even with IRC where it's completely possible to use a different handle per session you'll have people who decide to use just one in multiple sessions, or in different servers, or even services. Likewise, with XMPP there's nothing stopping you from creating different JIDs for different purposes. Or just using one for everything.
Being careful with opsec is something that will always be responsibility of the end user, and no protocol can do shit to prevent an user from doxxing himself. Authentication being in the spec itself just avoids the issue of leaving decisions about it to specific client and server implementations.

only Rob Kike would disagree with that

What is the best XMPP server program?

Sounds pretty gay OP. Maybe it's right up your alley!

I'm honestly disappointed I started off sounding like a fagoli post

XML is not extensible.

And what if that built in mechanism is flawed? Then everyone on every network is owned. Maybe that's already the case and that's why we see constant shilling for this protocol.

Matrix is better

I can see your glow from here

Lies.