[rubyn00bie]

I see a difference, but it's not in favor of PIs because they're physically separated.

I think it's far more realistic to choose a hypervisor (KVM, raise the roof) install it and configure it, run N virtual machines on a single machine, provisioning and slicing the hardware, setting up and managing the network between them, having disks run in a raid so the VMs don't starve for I/O and data is replicated, and then running kubernetes (or whatever personal hell you want) within your "virtual cluster." That's the whole "running a cluster" part all of these Pi Kubernetes things miss because they're running on consumer grade hardware.

Your hosting provider is surely not using thousands of small under-powered machines running bare metal installs of your applications.

Want to find out how resilient your cluster is? Just fucking kill one of the VMs. Boom. Instant feedback. Now try that with a PI, you'll have to unplug it, and then wait five minutes for it to boot. It becomes tedious fast.

Clustering and distributed systems are extremely complex and difficult... just having physical machines doesn't really even begin to scratch that problems you'll face, just my two cents.