> I just don't get why people love this.

For a single personal user it's only a small bit of friction but if you're in charge of 30 people SSO is a godsend for boring compliance work and managing groups of people. You want to change a domain in the company not a big deal. Don't have to rotate passwords every quarter, need to restrict an employee from a service etc. You aren't imagining other challenges other than your own here.

That is an interesting take, but it's off topic.

The post says that if you don't have the SSO, it's a conversion killer. I.e. users just won't log in if they cannot do it with an SSO.

Of course companies use SSO because it gives them more control over the employees accounts. I understand why company do it.