We are in the process of switching to Gradle at work and I'm not sure I like it. I used Gradle when building some OSS projects, but my experience wasn't that great.
Just make sure that whoever writes the majority of the build file actually understands gradle, at least its fundamentals. It really is not hard, and afterwards it is a really great tool that can significantly improve compile/CI times.
The tool whose main purpose is to build stuff should not demand "understand gradle at least fundamentals so that afterwards you can probable possibly improve times".
Why isn't it fast out of the box? Why does the simple "provide a list of deps, provide a list of paths, build" take so darn long? Because Gradle is a great tool or something?
Don't forget that it's also already at version 8, where each change is mostly incompatible, bizarre and inexplicable breakages between versions, often due to meaningless option renames. Imagine if they spent all that effort on actually making it a great tool.