Without use of simulation L4 can never be achieved, most companies will go bankrupt and many people will have to be harmed needlessly along the way. The problem here and in this industry as a whole is this simulation being used is nowhere near good enough to allow most of the development and testing to be switched over to it. There are simply too many gaming based architecture and active sensor modeling issues. The tech used by DoD/aerospace resolves all of this so a legitimate digital twin can be made to facilitate the paradigm shift.

Simulation can create a Complete Digital Twin of the Real World if DoD/Aerospace Technology is used

https://medium.com/@imispgh/simulation-can-create-a-complete-digital-twin-of-the-real-world-if-dod-aerospace-technology-is-used-c79a64551647

Simulation Photorealism is almost Irrelevant for Autonomous Vehicle Development and Testing

https://medium.com/@imispgh/simulation-photorealism-is-almost-irrelevant-for-autonomous-vehicle-development-and-testing-136871dee440

The Autonomous Vehicle Industry can be Saved by doing the Opposite of what is being done now

https://medium.com/@imispgh/the-autonomous-vehicle-industry-can-be-saved-by-doing-the-opposite-of-what-is-being-done-now-b4e5c6ae9237