And Virtualized is good because we don't want to "waste" a whole machine for just a file server.
Hmm. I strongly disagree. You've created a new dependency now for the fileserver to come up - a system that many other services will also depend on and which will likely contain backups.
A dedicated system is less likely to fail as it won't be sensitive to a bad proxmox upgrade or some other VM exhausting system resources on the host.