In large scale computing, a server will have VERY powerful hardware. You can run multiple VMs on that one machine, giving a slice of that power to each VM so that it basically ends up with multiple individual computers running on one very powerful set of hardware instead of building a ton of individual.
The other key feature being cost. A VDI terminal is much cheaper than actual PCs for employees. When I was working IT for a large company, we were able to get them in bulk for about $100 each. A PC cost us at least $800.
Similar to docker, but the technical differences matter a lot. VMs have a lot of capabilities containers don't have, while missing some of the value on being lightweight.
However, a more direct (if longer) answer would be: all cloud providers ultimately offer you VMs. You can run docker on those VMs, but you have to start with a VM. Selfhosted stuff (my homelab, for example) will also generally end up as a mix of VMs and docker containers. So no matter what project you're working on at scale, you've probably got some VMs around.
Whether you then use containers inside them is a more nuanced and subtle question.