But this work scales better than linearly. One sysadmin, if doing their job properly, can configure a robust backup solution once and it will apply to many diff

But this work scales better than linearly. One sysadmin, if doing their job properly, can configure a robust backup solution once and it will apply to many different programs. Machines in a DC can be set up once and host many programs. Login is surely one of the best arguments for non-SaaS solutions. SSO is a total mess in the SaaS world. Everyone ends up with a billion passwords that they manage individually, change at different times, have to use a password manager to keep track of (but they all use different ones), etc. Active Directory is actually a solution to that which got lost in the move to SaaS-in-the-cloud.