A long time ago, when I had a bunch of 68k Macs, I had an AppleShare server running Debian. I even served MP3 files to iTunes using a DAAP service. At some point I set up a Time Machine system for the newer machines - the trick was to broadcast a specific machine type so that the Macs would recognise it.
They also sold rack mountable Mac servers known as Xserves for nearly a decade...
https://en.wikipedia.org/wiki/Mac_OS_X_Server#Discontinuatio...
It appears that Apple ensures that enterprise/server use cases remain safe, legal, and rare. My estimates of zero rackmounts and zero servers was an exaggeration, but I'm curious if the comparative percentage rises beyond a single digit.
I must confess: I yearn for the days when AppleTalk was an absolutely amazing peer-to-peer networking solution, and when it ran rings around anyone trying to cobble together an ad hoc 10Base2 LAN in their office.