Let me clarify my position: Tesla does not advance self-driving research, and they don't need to. Tesla won't be the first to release fully self-driving cars. (I think 'SAE levels' are bunk, but let's say this is level 4.5 for the sake of discussion.)
EDIT: Sorry, and to clarify, I meant "not a player in self-driving research. I also do not think anyone has any vehicles we should call "self driving".
(I'll keep the rest of my pre-edit clarification below.)
To clarify further:
Tesla's offerings come from applying and engineering existing published research. That takes work, and they're making some money from that.
To the extent that "fully self driving" is an achievable goal, it makes no sense to expect Tesla to make the advances that get us there, when (1) they aren't doing that, and (2) they don't need to do that to make money.
To make this even more clear, let's make it concrete with one plausible future: In 2032, Waymo (or Didi, whoever) achieves true 'level 4' fully-self driving with proprietary technology. Their tech is seen in trucks, busses, taxis, as well as being equipped to a few thousand private vehicles. The safety stats are superhuman, and insuring such a vehicle is cheap.
In this future, Tesla Motors would like to enter into an exclusive partnership to integrate this technology into the cars they manufacture.