We build non-technical SaaS software targeted at anywhere from pre-IPO to Fortune 25 companies. I'd say SSO is a hard requirement for at least half of our new customers (which to them means SAML 2.0 - ADFS, Azure AD, Okta, OneLogin, etc). And this number has been rapidly growing in the last 2 years as companies become comfortable with using cloud-hosted SaaS solutions rather than on-prem.
While it may not be the prettiest protocol, today it is the only broadly supported SSO option that does not expose your credentials to a third party. LDAP was the way to go at one point, but this only makes sense for on-prem software where you can trust your credentials to flow through.
Also, I am pleasantly surprised by the number of orgs that are introducing regular key-rotation into their SAML iDPs.
While it may not be the prettiest protocol, today it is the only broadly supported SSO option that does not expose your credentials to a third party. LDAP was the way to go at one point, but this only makes sense for on-prem software where you can trust your credentials to flow through.
Also, I am pleasantly surprised by the number of orgs that are introducing regular key-rotation into their SAML iDPs.