The old package managers messing up the global state by default is the reason why Docker exists. It's the venv for C.

Because a single docker image can run multiple programs that have mutually exclusive dependencies?

Personally I never want program to ever touch global shared libraries ever. Yuck.

> a single docker image can run multiple programs

You absolutely can. But it's not best practice.

https://docs.docker.com/engine/containers/multi-service_cont...

God I hate docker so much. Running computers does not have to be so bloody complicated.