It really depends on what the goal of your server is. I have two licenses. I run HexOS bare metal, where the main purpose is data storage and backup. I also have a Proxmox server that runs a HexOS VM.
I use Proxmox with PBS as my virtualization platform and HexOS/TrueNAS for storage. However, HexOS/TrueNAS can also be used as an app and virtualization platform. To some extent, Proxmox and TrueNAS share similar functions, but each has its own focus and strengths.