docker ps
or Portainer as a nice web-UI wrapper around the Docker commands are the two main use cases with Docker I have have on a regular basis.
No, thank you. I am not going to maintain fifty containers and fifty + X volumes for just a handful of applications and will alway prefer self-contained applications over applications that spread over multiple containers for no real reason.
I think the reason is stupid and it is contrary to what I expect from dockerized applications.