The flip side is economies of scale.

Github can implement code search, credential scanning, malware scanning, or any other number of other things and theoretically, every code repo can get it for free.

When everything is centralized, adding a new feature costs k but gives N benefit. When there are M different options adding a new feature costs k * M for N benefit.

I don't think it's as black and white as centralization is bad, but I do agree that it gives microsoft undue power and that power can be a force for good or evil.