As I see it, the lineage of modern automated cars started with public funding from DARPA, with the first signs of success appearing in 2005:
https://en.wikipedia.org/wiki/DARPA_Grand_Challenge
After the DARPA Urban Challenge of 2007 I naively thought that commercial self driving urban vehicles were about 5 years away. It actually took until 2020 for Waymo to offer services to the public, and just in one city to start:
https://en.wikipedia.org/wiki/Waymo
That's a long timeline from "tech demo" to usable technology. I don't know how to maintain government funding for that long in a democratic system. No president, senator, or representative goes that long without fighting for re-election. Any technology that still isn't working after 12 years is likely to be considered a dead end and canceled. The big impressive government projects of the 20th century delivered results faster; there were only 7 years between Kennedy's "We choose to go to the moon" speech and NASA actually landing on the moon.
Companies with large resources can behave more like "planned economies" that aren't subject to short term whims of the electorate. Of course they can also exhibit even more short-term orientation -- the notorious "next quarter's earnings report" planning horizon.