@Paddy3101 - I think you missed a wrinkle. Elaborating...
As the performance of the "L5 FSD candidate system" improves, insurance companies and regulators will likely be motivated to incentivize humans to "let the car do it" to remove the unpredictable humans from the roadways. I expect much of the tail of edge cases to be directly caused by the "cohabiting" human drivers. If/when the human drivers are removed, the self-driving car performance numbers will improve overnight. I suspect that can be proven statistically in test markets pretty easily.
In other words, if you can get Jimmy to let the car drive he becomes safer and the self-driving cars around him become safer.
Yup. That's when shadow mode gets reversed, and to get cheap insurance you have to let the car watch as you drive and intervene if you go to do something stupid.
We're certainly not close to something like that yet - if nothing else, 98% of the new cars on the road don't have the equipment, and we currently turn the fleet every twelve years or so - but if FSD is as mature as it looks, I suspect we'll see nearly mandatory shadow boss mode in my lifetime in at least some jurisdictions.