I know little about gradle and have only just started exploring it, so this is just a question out of curiosity.
It’s supposedly a language agnostic dependency manager and builder, yet it seems to have only found its niche in Java. C/C++ projects could definitely do with dependency resolution…
Programming languages come with their own niches, tools, culture, and history. Gradle has lots of verbosity, complexity, and so on. It’s a build system and a dependency manager in one. Other languages separate these duties.
A cultural preference for tools written in specific languages or available for specific platforms exists as well. Lots of C/C++ programmers dislike everything Java. They will cite performance and philosophy. They ask why should they install and manage JVM versions and installs for a task they can do with a make file, a shell script, and Conan/vcpkg.
Not even all Java folks use gradle. maven and ant ant are still around and I’ve seen someone write Java build tasks using rake.