I have on occasion seen them used correctly, or more accurately tried to be used correctly. For example, I once managed a team where the PO overloaded them with 3x the amount of work they could complete every sprint. So I showed her the velocity chart to demonstrate that there was no way in the world that they could complete so much work. Her response was "let's try anyway". I have previously written that the main reason velocity exists is in order to fit work into fixed sized Sprints, so maybe the Sprints themselves are the problem:

https://medium.com/catum/hurry-up-for-the-sprint-deadline-is-approaching-f17925e4752b

I agree that when it works well, it can indeed work well. But that is a mighty difficult (and rare) task IMO.