Regardless of how advanced technology becomes, flying objects have inherently more momentum and since momentum is based on velocity squared, the strictness of regulation of flying vehicles should never be less than an order of magnitude more than ground vehicles of the equivalent weight.

speed/energy and reaction time of human or control machinery dictates separation distance. Thus drones for example can hover much closer to each other than say a separation distance between human controlled cars doing 90mph on highway.

Most of the new aircraft development would contain a lot of automation to the point of self-flying. The dense network of automated traffic control for such new aircraft would be another thing that only billionaires could really do. That would allow to take out of equation a lot of human errors that make current aviation dangerous.

And when the automation fails or the vehicle malfunctions who will take on the liability?

And the liability is inherently far greater than ground vehicles. For example, right now it’s practically impossible to accidentally drive a ground vehicle, certainly not something less than a ton, into highly sensitive places like the pentagon/nuclear weapons storage facility/military base.

But it’s very easily imaginable that an automated aircraft less than a ton could fly itself into such a place, accidentally or intentionally, and cause a serious kerfuffle.

Or to put it another way, it’s thousands of times more costly to protect airspace from intrusion than ground space.

To cover the possibility of the owner being unable to pay out to cover the costs of disruption, liability insurance similar to car insurance would likely be mandatory, just thousands of times more.

If flying vehicles became deregulated and instead had a mandatory minimum insurance requirement for $1 billion of liability then it’s effectively the same. Because that’s the realm of very serious folks with large legal teams anyways.