The fact is, for the overwhelming majority of the world's roads, the technology is not mature. They will probably never be suitable for mass adoption in the second world, nor anywhere else where roads are poorly marked, unmarked dirt, ill-signed or prone to wash-out or sudden changes. Ergo, 90 per cent of anywhere in the world that's not a first-world population centre or roads directly linking these centres.
The further fact is, at no point prior to the self-driving car, did I hear anyone, ANYONE, say 'you know what tech I really wish I had right now? A self-driving car'.
But self-driving cars we have. To be completely honest I have strongly suspected, right from the outset, the technology's main product is power. Data collected will be very valuable but in the end the true product being sold to the governments who regulate the industry is the ability to monitor, surveil and if necessary deny the movements of the population at large, and persons of interest in particular.