In the long run, if there is competition, it should drive down costs. If the sensors / compute hardware / software costs more than the labor of a human driver then self-driving vehicles won't be viable, but the bet these companies are making is that it will, and in the long run, those costs will be amortized. And if the costs of offering a robotaxi service are lower than a human-taxi service, and if AVs are not a monopoly, then the price will eventually end up cheaper as well.
