Wat?
Wat?
Apple's icloud is partly their datacenter running a mix of systems/hardware and renting out Amazon and Google cloud units, which are Intel/AMD.
Google populates it's datacenters with their own servers. So does Facebook. So does Amazon. Netflix builds their own CDN appliances. Apple absolutely could if they wanted to.
Buying a beige box to put an intel chip is not "your own" servers in the context of this discussion. I'm not sure why you're so rude and confrontational here. We're discussing how Apple has top to bottom control in its consumer devices, not some weird discussion about datacenter packaging. Servers run on AMD/Intel and as such are stuck with the elements of those platforms AMD and Intel dictate. That's not having the entire stack to themselves.
Using today's MacOS as a server is an exercise in pain, largely because there are a number of routine server administration tasks that fundamentally require the GUI in MacOS.