The os should already be an irrelevant host for processes, if developers stopped with this dynamic linking and spreading files and configuration all over the os, instead of a simple contained directory with all it's dependencies and configuration except for the kernel. Like we did in the good old DOS days.
When it gets interesting is when you invert the relationship, where you have multiple apps in Docker. Then the main server starts to look quite simple and bare, much easier to maintain. And then things like ECS start to make sense:
https://aws.amazon.com/ecs/
At that point, the OS becomes irrelevant except as a host for containers.