Not really, we have a full-blown REST API that provides storage plugins for a dozen of technologies, disk management, system metrics reporting, management of LXC and QEMU (as in full-blown LXD/Incus and libvirt replacement), which alone probably is taking up a third of our code base, to provide replication, live-migration, local-storage (live-)migration, backup management, HA, good integration into our access control management including multifactor authentication, integration in to LDAP/AD or SSO like OpenID Connect, software defined storage and network integrations, our own kernel, qemu and lxc builds, and hundreds of other features. Don't even get me started on the devs required on each project to continue integration and upstream development and provide enterprise support that actually can fix problems.
In other words, wrapping QEMU or LXC to provide ones custom VM/CTs might be doable easily, but that isn't even a percent of what Proxmox VE offers you.
If a thin UI around LXC/QEMU is all one would need to be competitive with VMWare, then every web dev would be stupid to not create one as a weekend project, but reality is that there's much more required to actually provide the whole ecosystem a modern hyper-visor stack requires to even be considered for any production use case.
And Proxmox is just skin on lxc and quemu/kvm.
I will say that as I have just started playing with the lxc api, having the Proxmox UI as a quick and easy visual cross check has been lovely.
Podman is an amazing alternative to docker, cant say enough good things about it.