Any build system is a nightmare when you don't understand it. I don't know what that team moved to Bazel from. I suppose it was Makefiles, and I'm sure if that'

Any build system is a nightmare when you don't understand it. I don't know what that team moved to Bazel from. I suppose it was Makefiles, and I'm sure if that's what the team was using, almost all of those 25 people did not understand them either. What parts of Bazel were a nightmare? What problems were fixed by these 4-5 people that were previously impacting all 25 people routinely?