I mean if you are talking about one server, I would just throw it on the cloud, schedule snapshots, sync file level backups with s3/blob storage and call it a day.
This is true, but it's still virtual. He's asking why would you virtualize just a single server (on premise) if that is all that would be on that host.
The OP is just confusing to me. Why would be want to buy a dedicated server to run one VM?
Sometimes you have to. Canada has a law where when users in your company are accessing data the data has to be contained in Canada. This is specific to our category of business, but it exists. I just priced out a server for this exact reason.