Maybe it should be more stressful. VR can deliver this, preferably with real driving controls and full physical motion like a professional flight simulator.

VR would let people practice with kids running out in front of the vehicle, with moose on the road, with spins on ice, with downed power lines, with floodwaters, with a blown front tire at highway speed, with the car in front swerving to reveal a sofa on the road, with windows suddenly fogging up, and so many other troubles that are hard to safely practice in the normal way. VR would let us train people to avoid rolling a vehicle off the road in a panic when an animal crosses the highway. VR would let learners drive for 6 hours of monotonous highway in the dark, proving that they can do it without becoming too drowsy to operate the vehicle.

My driving instructor was very stressful (lots of yelling at me and other drivers), but given the sheer amount of bad drivers on the road these days it ended up being helpful - when "stressed out" is the baseline when you're driving, you either break and find a different instructor or unlearn the stress response and stay calm while driving.

I've narrowly avoided several accidents caused by other drivers (running red lights at intersections, changing lanes without looking and nearly running me off the road, road rage, etc.) which I partly attribute to being able to stay calm and make the right decisions to avoid an accident.

No matter how good they are, if an accident were to happen, I would want the presence of a human, if nothing else because you need one person to administer first aid while another gets help. If I was on my own I would probably be panicking too much to help.