You are correct there is a systems approach needed. problem is ytou are still thinking from inside the same echo chamber.

It is a myth that using public shadow driving is the best or only way to create this technology. That the casualties it has created and will create are necessary evils. And that this technology will ever lead remotely close to a legitimate driverless vehicle.

It is impossible to drive the one trillion miles or spend over $300B to stumble and restumble on all the scenarios necessary to complete the effort. Many of which are accident scenarios no one will want you to run once let alone thousands of times. You also cannot survive the thousands of needless casualties you will create trying. And finally, as the public, press and governments are figuring out, handover cannot be made safe for most complex scenarios, by any monitoring and notification system, because they cannot provide the time to regain proper situational awareness and do the right thing the right way.

But there is a better way.

SAE Autonomous Vehicle Engineering Magazine

End Public Shadow Driving

Common Misconceptions about Aerospace/DoD/FAA Simulation for Autonomous Vehicles