Why? We literally never see that with top shelf products. This isn't an arduino solder job. This is going to be an integrated software and hardware package that will rival an aircraft autopilot/navigation. Please check you facts on the cost of these things.
I don't want walmart brand, everday low price components on my self-driving vehicle. I want top of the line if my life is in the balance.
Google claims that it dropped the price of lidar by a factor of 10x once it started producing them. That seems like a significant, factual, drop in cost.
These are all things that started high and fell low. The historical prices for each of these systems reflects this fact, as does their gradual movement through the available product line-up. They all started in top of the line vehicles that cost well north of the average person's yearly salary, and are steadily creeping into the lowliest models.
I see nothing in self-driving systems that make them special in this regard. They're already largely an amalgamation of commodity components whose prices are trending downwards.
You can bet on them staying a niche product forever, if you wish. I just think it flies in the face of historical evidence.