But this can literally just be done in a simple shell script as well.
The makefile ends up just being a redundant way to run a shell script.
Only if there's no dependencies. It's unusual that GP's type of usage has no dependencies.
I hear you, but you're running the other script unconditionally. If it downloads something, it will download it every time you run the first script.
In this simple case, make runs the other script conditionally, so it need not run every time.