How can a car that cannot fly be almost as good or better than one that can? That’s apples and oranges.
Like saying that corvette is better in many ways than that cessna.
A flying car can get you places faster.
An autonomous car allows you to sleep why getting there, effectively using time that you would have spent driving.
A flying car avoids congestion on the roads.
An autonomous car avoids congestion through superior knowledge of whats ahead.
There are problems that both approaches solve, in different ways.