I believe some other distros also have UEFI booting/installers setup for PI4 and newer devices because of this, though there's a good chance you'll want some of the other libraries that come with Raspberry PI OS (aka Raspbian) still for some of the hardware specific features like CSI/DSI and some of the GPIO features that might not be fully upstreamed yet.
There's also a port of Proxmox called PXVirt (Formerly Proxmox Port) that exists to use a number of similar ARM systems now as a virtualization host with a nice ui and automation around it.