That's a long way away. The self driving technology has plateaued after the initial controlled tech demos and isn't looking likely to be useful in the general way that Uber needs any time soon. Maybe they can get it working in some very favourable routes but not enough to balance the books. Some really hard problems still exist with algos and sensors and the costs will be high for a long time. If the bet is on autonomous vehicles it's a very long bet.

According to your logic there is no such thing as an actual millionaire. No sane person keeps a million dollars sitting in cash in a savings account, they invest it somewhere (equity, bonds, real estate, etc).

Touche :)