Ask HN: Ongoing support cost of SSO vs. email+password+MFA for enterprise SaaS?

The SSO Wall of Shame [0] got me thinking - would you all share anecdotes or research into the cost analysis of driving customers toward SSO vs toward local credentials (eg. email+passwored) plus Multi-Factor Authentication (MFA)? I'm especially interested in the ongoing support cost, but welcome thoughts around the initial setup cost as well as the pros/cons of the two solutions beyond cost. [0] https://sso.tax