I shouldn't be getting nerd sniped by comment about Maven but here goes. Maven doesn't compose because it is an ad-hoc lisp where every element has different semantics, every element is a different language. This isn't an XML problem, but a way that XML fragments in Maven map to the interpreters of those fragments. Maven could have been an amazingly compact expressive combination of a logic/constraint solver with a declarative language, instead it is PHP written in XML. Maven is declarative only in that it has a textual interface.

My disclaimer: my coworkers are using Scala and SBT. Gradle + Java isn't slower than Ant or Maven. Gradle + Kotlin is a little slower, they just need to make the annotation processors incremental.

But for Java, incremental builds with compiler avoidance combined with the build cache, parallel builds (incubating features close to maturity) mean I write more sophisticated, easier to maintain builds than I ever have with Maven.