It's particularly common with big whale enterprise clients, where the salesperson is trying to close a very long sales process or the client has you by the short hairs in the contract. I remember one case where we had to implement a very complex and time-consuming custom SAML integration to a platform where we just had one client asking for it, because that client was too big to ignore. Once we integrated SAML, the number of end users actually using the SAML login option was in the single digits. It was just a checklist item for some purchasing officer flunky.