But is Tesla doing that? Their thing has been that they refresh/fix their cars through OTA software updates, not tweaking the physical vehicles to any great extent. Indeed, my understanding is that prior to the Highland refresh, their two large-volume models (3 and Y) have been largely unchanged, in terms of physical design - which is what led to some of the calls that the 3 needed an update. Plus, it’s not like Hertz’ fleet was purchased an especially long time ago, either - those cars would have been two years old or so.
I think Goofy’s probably more correct on this. It’s hard to get parts because Tesla hasn’t done what’s necessary to make parts easy to get.