There's some more to consider with the latest buildkit frontend for docker, check it out here: https://hub.docker.com/r/docker/dockerfile

In particular cache mounts (RUN --mount-type=cache) can help the package manager cache size issue, and heredocs are a game-changer for inline scripts. Forget doing all that && nonsense, write clean multiline run commands:

    RUN <<EOF
      apt-get update
      apt-get install -y foo bar baz
      etc...
    EOF

All of this works right now in plain old desktop docker you have installed right now, you just need to use the buildx command (buildkit engine) and reference the docker labs buildkit frontend image above. Unfortunately it's barely mentioned in docs or anywhere else other than their blog right now.