They depend on public investment to build and support road infrastructure. If one accepts your point of view, these companies depend on massive government subsidies. Or perhaps they should pay for the construction and upkeep of the roads their vehicles use.

By law, the English king could do what he pleased to. Somehow most folks still think the American Revolution was just.

Public transit and public places will continue to decline in cleanliness and quality for as long as the rich suck resources out of local municipalities.

They do the same things with public schools (pulling educated teachers to teach in private institutions) and with medical care (pulling physicians into private concierge practice).

If all the rich people had to take public transit and send their kids to public schools, they'd start investing money and (human) energy / capital in making the public infra better.

The investment of resources by rich people into their own private enclaves is entirely rational and can be solved only by wealth taxes that preclude such action (by making it impossible).

Why are usians still allowing homelessness?

This is not true. If a king has all the money, then whatever the king wants is what society builds. The use of resources by tech companies to build self-driving cars uses resources for things that might otherwise have gone to some other approach.

Google's use of resources does not occur in a vacuum. Moreover, if cities decided to pass laws that would slowly transition all road infra away from private vehicles to shared public transit, then Google would lobby against that.

For public transit to function well (i.e. competitively with private vehicles), traffic needs to be much reduced (e.g., imagine no traffic lights and no traffic). Google's private cars on the roads do not move us in that direction. There is no doubt that they are technologically impressive, but they do not provide greater utility than investing in shared infrastructure would.