Average car lasts 12-16 years. "If" this technology decreases accidents by even 50%, that would save 20-25k lives a year in the U.S. If it can decrease deaths by 75% that's around 32k a year less deaths. This doesn't include permanent injuries.

The last three auto deaths I have discussed with patients would all have been avoided if they had been using Tesla FSD I believe, even where it is now, including a 23 year old young woman who drifted off the road (fell asleep?).

Like seat-belts, this technology could become manatory quickly. I agree, it will take time, but could happen quite quickly. Older cars would get weeded out over the following 12-16 years or so of their life. But there would of course be many new cars with this life saving technology.