I don’t understand your disbelief here, the 2 major players in online email and account mgmt (for education) are Google and Microsoft and both are 0 cost, but the bait and switch is the limit lowering mid cycle, not even on the academic calendar. Now that exchange on-prem is essentially dead and Google and MS control email via blacklist politics, it’s a captive market.
I totally agree…the best solution for the specific problem. “Cloud” was the buzzword solution to every problem for a few years and it wasn’t great in a lot of cases. High I/O home grown apps to be used from a single campus don’t need to be in the cloud. Bulk archive storage doesn’t need to be in the cloud, things like lecture recordings from 10+ years.