I think it boils down to the fact that infrastructure for projects (no matter the size) is usually a second class citizen at best.

Either no one is eager to care for it, or the people who are actually focused on developing the software run it because they need to, or worst case - no contributor is trusted enough to handle infrastructure work, with access being given even more sparsely than commit rights to the whole software. Which is fine by itself, but there are so many (big) projects where infra is kind of terrible because 3 out 100 people involved are doing all the work. Or don't.