I think you greatly underestimate how hard it is to find a good build engineer. Two of the smartest and hard working engineers did a bazel migration at one of my old companies and had to contribute heavily upstream to support all of our use cases.

It’s much cheaper in the long run to migrate to a well supported tool that you can extend than have to continuously staff some of the best engineers to keep building on your homegrown mess.

This comment is reminiscent of others i have seen about “building uber with 20 engineers” what could be so hard?