Well, the monster wearing broadcom skin fucking over vmware licensees makes for a very interested market.
There's a lot of stuff that even if you put majority in the cloud, you want local deployment for security (inc. "operate when internet is out" security/reliability) and latency reasons.
For various reasons, vmware was pretty strong contender in this. Oxide racks are comparable in "sanity of mind" in deployments, and last time I was in a company that could use that the only major breaker was lack of ability to ship a raw VLAN to a VM, to enable direct replacement of existing vmware stack. But if it's not already fixed, it is not particularly hard to fix.
Surely vmware licenses are more easily replaced via Proxmox? Why would you care about Oxide, which is a hardware vendor?
Proxmox is fine if your vmware deployment was quite small. Single oxide rack at max density is going to similar values as official scaling sizes for proxmox, and very much isn't limit of what we did with vsphere.
And Oxide sells a complete hardware + software solution, including virtualization and SDN - essentially it's a physical equivalent of up to 32 node virtualization cluster per rack, with builtin SDN and SD-SAN, that already has features to combine for more.
Is this about limits to what the Proxmox folks will officially provide support services for, or perhaps what can be comfortably managed in the Web UI? These are very valid concerns either way, but the Proxmox VE software itself does provide a comprehensive API and that should scale quite a bit higher.