There's no real need for anything in life other than food and shelter. If driverless cars work and don't cost much, some people will use them and enjoy them and that's enough.
There are levels above food and shelter. Having a car is a real need and it solves a problem for lots of people. However having a self-driving car may solves some people's problem but that don't seem to big part of human population. I think that makes the development of self-driving cars slower.