I don’t really understand what this premise has to do with Tesla. It seems to be largely based on how you imagine things are, rather than how they actually are. I’ve had mine for several years and it’s almost never needed service of any kind — much less than more conventional cars I’ve owned in the past in part because of the pushed updates that I get on a regular basis. It’s self-driving proficiency and accuracy keeps improving. The biggest impediment seems to be lousy infrastructure with poorly marked lanes and the like.
The worldwide demand for the Model 3 is high and it’s the sixth best selling car in the US. Demand for the Y is expected to be double that. Based on demand and continuously improving capabilities even for cars that have been off the lot for years, I think it’s highly likely that a lot of people will be driving true AVs in a relatively short period of time.