“I’m sorry you merged WHAT upstream? No I don’t care if there’s a new glibc out there, the one we have works just fine.”

You can do SSH tunneling over DNS, so everything is possible.

A proper server should have one user per service.

The software can be open source, the product is branded and published.

What are you using for SSO?

sshd

The web is already federated. Anyone can start their own web server and compete with everyone.

The problem is WEI will prevent you from using unauthorized browsers with, for example, Netflix or YouTube or your bank, if those services decide to force WEI.

Federating those services is near to impossible for various reasons. People could make competing services that don’t enforce WEI, and some people have.