I generally see docker (used) as a second tier isolation. IT hands out VMs to vendors/teams, and then the vendor/team spins up 3-4 containers in that VM to suit their needs.
I'm aware it's technically possible to have a large, wide fleet of containers...but I don't really see it going that way (at all).
My current thoughts of why is separation of knowledge - IT knows how to manage infra and virtualisation, and the vendor/teams know how their individual docker containers need to be set up/work.
I do agree full virtualisation is probably on the decline, but the current tech is definitely staying around in my size of business.