My opinion is based on my experience integrating artifact generators (both code and config) into a build. I recall being funneled into building a plugin by documentation to deal with some idiosyncrasies of the generator. Whereas I just wanted to write a small script. In general I felt like there were a lot of extra hoops and concepts to learn to do basic easy shit. And there really isn't any payoff. For example I recall scripts and plugins have different capabilities. And that some things can't be expressed in untyped Gradle.

I also found that the user documentation was just a skosh above useless. It felt like it was more concerned with not being wrong than being helpful. Reminiscent of older javadocs in the java collections library.

The same could be said of many build systems, I suppose.