[nikau]

Containers have never been about system efficiency, rather admin/developer efficiency - lower skilled staff can pump out a working product cheaper.

Need to run 2 separate apps that both need to use the same userid/filesystem path/network listener port? No problems.

Need to have different library versions? No worries.

Sure you can workaround all this stuff with ld preloads and other things, but that requires more skill than copying a base dockerfile from a google search and putting in a bunch of RUN commands.