I see. We work pretty much exclusively on Ubuntu, and I've no experience at all with Proxmox.
I can say that in my own personal experience, I found administration with ZFS infinitely more friendly than LVM, to the point that I began pushing all our admins to use it even though they mostly had experience with LVM previously.
I agree ZFS is so simple to use and get going. I'd honestly prefur to use it, especially versions new than that available on Proxmox are said to be leaps and bounds better.
I honestly never really thought to simply use ubuntu as my host system. Figured it'd always be easier to use something that has a nice interface for making VMs and managing the host like proxmox, unraid, various platforms like that.