It's also better from an architectural separation perspective. Your custom CLI will have custom commands and flags, and probably will need to be called in some standardized way. Make is very good at calling your toolchain / build-system (whatever that might be) with the exact arguments that you want. And things like "make all" or "make clean" are muscle-memory for hundreds of thousands of developers.
Why mix your custom tooling with the task of standardizing an entry point?
I've had really great success over the years with the pattern of "some build system or another (cmake, bazel, autotools, etc) orchestrated by a top-level Makefile." It's simple, portable, and flexible. What's not to like, other than ugly syntax?
But how is make dependency free? You need to install make. Which version? GNU make, or FreeBSD make? What platform are you installing it on? What version? In my team we had to get all our devs to manually upgrade from 3 to 4 as we were using modern make features to make it a nicer task runner.
These are all things you've already had to deal with in the custom CLI, which is also a perfectly good entry point. You also have a lot more control of command line arguments, rather than just make targets ("just" has also added this as a feature)
