Edit: Now that I think of it, it's possibly still a huge cost savings in that you can have interchangeable parts across all models, since the vents are hidden to the user.
The Tesla vents are great, the ui is good or can use voice. Other companies that attempt what Tesla does do it poorly with bad software.
Which cars are you driving where they break often?
My experience is that as the car gets older it is common for the vents to lose the capability to stay pointed where I place them. As in: you point them where you want and they flip back all the way to one side as soon as you let go.
(Hot climate here, with several months of "a/c set to max during the whole trip" per year)
More modern cars of decent build do not have this issue.