I would like to move my servers to virtual machines. This is because it'll make it easier for me to fire up more machines and back them up in case the physical server is damaged (I'm not aware of other benefits). While I use virtual machines normally as isolated workstations, I'm not aware of the full set of their benefits for servers. What I mean is: I see people use (and promote) VMWare vSphere for this. More licenses seem to cost more (exponentially), and I don't know why. I'm wondering whether lxd (It's like docker, but persists its state) is a replacement to this.
What are the benefits of using a virtual machine (vSphere specifically or generally any other kind) over using simple containers like lxd?