For me it’s convenient in some situations to be able to have full control over the generated makefile. That’s what using a macro language really gets you. It’s just not an option for other build tools that want to support multiple makefile backends. (cmake, meson, etc) And it somewhat causes problems for automake too which complains at you if you use any GNU make features because they aren’t portable. That leads to annoyances like having to use stamp files which then make the makefiles long and confusing and hard to maintain.
I don’t know if I could recommend it for a general use unless somebody really needs one of the uncommon systems that autotools supports.