No you don't. I like makefiles because of the dependencies between targets but for simple multi-target things I still do shell scripts like

    mything() {
      # ...
    }

    otherthing() {
      # ...
    }

    if [ $# -eq 0 ]; then
        echo "Usage: ./run.sh [mything, otherthing]"
        exit 1
    fi

    "$@"

I've been writing scripts like this but with a case/esac at the bottom to map $1 to the right command. Have never thought about doing this instead. thank you for opening my eyes!

Been There, Done That, Bought The T-Shirt and leads to unmaintainable shit. One script per action. The end.

Maybe for your usecase, sure, but my usecase is my own dotfiles which has some of these helper scripts and it's a good fit there.

You express no nuance and only say that something is wrong without explaining why. Your communication skills lack "skill" and "communication". Your absolutism makes me convinced that you are are either wrong or incapable to explain why you would be right.

Why is that a better UI?

wth. makefile can include other makefiles.

That's a god function antipattern and rapidly becomes non-portable.

Each lifecycle hook should be a an executable of some sort like "scripts/{{command}}", be it a shell script or something else.