I deal, with mid size (200-800) people and there is no k8s or serverless to be seen anywhere.
Personally I don't have a huge amount of experience with either, so I'm possibly a bit biased, but I see k8s as either a hyperscale solution or someone wanting to be cool and trendy.
Same goes for serverless, other than niche use cases of say running python code in a 100% Azure ecosystem when you just have absolutely zero other choice.
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.
I suspect the strategy is to extract maximum cash whilst they can.