I also work in the industry. You've got a couple misconceptions here about how AVs actually work. First, virtually all processing to determine what to do on the road is done locally, in real-time. Relying on internet connectivity would be a safety nightmare. This means you have to pre-train your models to deal with everything in a geofenced area before the car starts driving there. Hence the need for very high detail maps of the areas where robotaxis are going to run. Second, the concept of L3/L4/L5 driving doesn't quite match the reality of how things are playing out. Due to the limitations and cost of deploying current-gen self-driving systems, AV companies are designing vehicles to be L4/L5 within a specified design domain. That means a specific set of roads under specific weather conditions, light conditions, etc. Then those design domains will slowly expand until one day, years from now, vehicles are actually what the public now thinks of as "L4/L5" and at that time it will be possible to deploy the tech for privately owned vehicles. Until then, you're looking at commercial fleet vehicles in specific use cases only (robotaxis, automated heavy duty trucks, farming equipment, etc.)