Dependency hell. Usually how it goes is you have to develop a new feature, you find a library or a newer version of the framework that solves the problem but it depends on a version of another library that is incompatible with the one in your project. You update the conflicting dependency and get 3 new conflicts, and when you fix those conflicts you get 5 new conflicts, and repeat.

So churn causes more churn.

Also breaking APIs should be regarded very poorly. It isn’t. But it should be.