Curmudgeon here: this was true for a relatively brief period of time. Nowadays I'd say that gradle has (inexplicably to me) taken the lead - and everyone adds custom crap to their gradle build making them far less predictable than maven builds used to be.
I guess it's better than the nightmare over in the front-enders' world...
I rarely see Maven files in non-trivial projects that are anything but a confusing mess of XML.
Granted, the constrained abilities do tend to keep folks from writing one-off snowflake build customizations, which is nice. But it still leave a hell of a lot to be desired. It was however, leagues ahead of Ant, which wasn't a high bar.
I saw a lot of that too - I just see more and worse with gradle.
Maven gave us two things; good dependency management and convention driven builds (removing the horrible scripted build stuff in Ant).
Gradle from my point of view took the second one away again and it feels like it was just because people didn't like XML and couldn't be bothered to learn how Maven's build lifecycle actually worked!
I guess it's better than the nightmare over in the front-enders' world...