Earlier quoted context omitted.
Several decades ago, I was hearing about flying cars. The technology existed for years. Commercial flight is a thing too, but 20 years later we're still no closer to having flying cars. Why would self driving cars be different?
The factors seems weighted very differently. Flying cars are even more dangerous than SDV (a flying ton near buildings ?). The technological soil of the era might be less nurturing than today.
Are they though? Statistically speaking, planes are safer than cars, and SDVs don't exactly have a pristine record track already.