These are great points. I would add that part of societal buy-in might involve driving the cost of hiring cars down by automating them, though I realize at the moment Waymo can charge a premium because people prefer to not have a human driver. Over the long term autocars should be cheaper than either Uber or owning a car yourself.
I was talking more about mandating or encouraging the tech in personal vehicles. I think there's plenty of buy-in for driverless taxis already. It's a perception thing - trust a stranger or trust an automated system. I think it's a much tougher sell to put it in person vehicles, especially due to cost.