I would argue it’s the correct idea up to a fairly decently sized business. Basically anything where you don’t have the budget or the need for super fault tolerant systems (i.e. where it’s ok to very rarely have a 20 minute to an hour outage in order to save 50k+ of IT hardware costs). You can take the above and go next step to a high availability proxmox cluster to further reduce potential downtime before you step into the realm of needing vmware and very expensive highly available and fast storage as well. It gets even more true when you start messing around with truenas and differential speed vdevs (i.e build a super fast nvme one with 10-25gig networking for some applications, a cheaper spinning rust one with maybe 10 gig networking for bulk storage. It’s also nice that, by using proxmox backup server as a zvol you can take advantage of all the benefit of both zfs replication/snapshotting and cloud (jstor/wasabi s3 bucket, another truenas server at a different location) for that zvol as well as your other data you are sharing as datasets.