Sure, it's better than nothing. And it does function, and it has (vastly) simplified adding third-party libraries. And there are much worse alternatives. But

Sure, it's better than nothing. And it does function, and it has (vastly) simplified adding third-party libraries. And there are much worse alternatives. But it's not debuggable. It's not introspectable. When things go wrong, you're left hoping Stack Overflow has a magic piece of copypasta to save you from days of guessing. To integrate with it you practically need to do what Android Studio has - work directly with the Gradle team to expose enough information to custom-build an IDE that can make use of it. It feels like it could've been achieved more simply by other means. Instead we have a truly massive, very slow build system that few understand, and for a long time (including after Android Studio's adoption) didn't support basic, long-standing features of the Java build environment (like "provided"-scope code (common in many languages! arguably universal!) and annotation processors).