A raspberry pi 5 would be a neat little stocking stuffer.

Because you're bound to use the GUI version of Windows Server, and besides things like Active Directory, Group Policy, SMB file shares, print servers, what have you, you won't learn as much as something totally foreign to you as a Linux shell interface.

That's my take anyway.

Even though live kernel patching is a thing, I generally do a full reboot every month or two for the next big patch.

Full shut downs? Are we upgrading them, dusting them, or doing any other maintenance to them? That would be the only case besides UPS failure or power outage.