many universities bought into the cloud offering back when it was still live@edu, shown as an upgrade path for existing on-premise dovecot/exchange systems. back then a student would be lucky to get more than 100mb for their mailbox, and maybe a gig of personal file storage (which was only accessible on campus or via a vpn, the latter many would not have access to). microsoft just offered a _better deal_ at the time

frog boiling means that many never noticed how big (and therefore unspecialised) microsoft was until it was too deeply integrated