While I agree your argument sounds good and probably works for many cases, the fact is that I would use the system described in the Tesla scenario and I would never ride a subway in a place like Texas or Los Angeles.

Public transport is absolutely gross and legitimately scary in Los Angeles. However, if I could stay in my car I would totally use this system, also having your car at your destination is incredibly useful and not something you can do with a subway.

IMO they both serve different needs.