Not to defend TSLA, but I don’t think self driving is the reason why Tesla cars sell, it is more about being arguably the best mass produced EV out there.
In 2018 this would be a really good argument. What does Tesla do better now, compared to another modern purpose built EV, for example a Ford Mustang Mach E, or a Hyundai Ioniq 5, Kia EV6, etc?
I struggle to identify any particular feature I would say they are better at, much less something that would make it the best mass produced EV. I say this as a two-time Model 3 owner, having just bought the most recent one two weeks ago. I don't quite have buyers remorse yet, but it's nagging at me that I may have just made a foolish choice for the wrong reasons.
As someone in the EV market I almost went for a Tesla for this reason.
They are not obvious winner among EV cars currently. They were first to do actual high end EV car and that vision changed the market back then.
Tesla also used to have reputation of being well build cars few years back. I don't know whether their quality went down due to mass production or whether it was just not known about them.