Will that driver be able to correct enough FSD mistakes to make the difference? If the accident and death rate is cut in half, I'd count us lucky that the problem to be addressed is in a piece of software that can be improved, versus a problem in people that cannot.
Fortunately, we won't have to worry about this because Tesla won't even pursue mass adoption until they're convinced that FSD's mistake rate is low enough to cut accident and death rates in half. Until then, it'll remain a toy for the wealthy, and the wealthy folks can continue to play the role of lab rat.
Here's the thing with FSD - are people going to engage it "so that they are safer" or are they going to engage it in order to offload some of the stress of driving. These are two very different cases, IMO.
Before I had FSD, I had EAP with nav on AP ability. I used this all the time for freeway driving, and for longer drives found I was much less fatigued at the end of the trip. I now have FSD-beta. For freeway driving, I'd say it's the same story. I'm less fatigued at the end of a trip. This is because it's capability is essentially unchanged from EAP+NoAP.
However, when using FSD in other scenarios (navigating through residential, business, etc. surface streets) I'm actually MORE fatigued by the end. I'm MORE engaged in a surface street trip with FSD-beta engaged, than I am just driving myself. HUH? That sounds wrong. But I think it's true. When I'm driving, I'm paying attention to everything around me and intuitively piloting the car through every scenario. When I'm playing back-up to FSD-beta, I have to do double duty. My brain is thinking of how *I* would do something, then observing how FSD does it (or doesn't) and then having to decide if I need to take over. Even when it's doing well in an "easy" zone, I'm still constantly on the lookout for it to do something stupid (which it occasionally does do). When I am driving, I'm not constantly afraid that I am going to swerve unexpectedly into another car. The OTHER car might do that to me, this is just a fact of life when driving, but *I* am confident in MY abilities and intuitive decisions.
Driving surface streets with FSD-beta on is a lot like driving with a 15 year old behind the wheel, who's still learning the basics and developing their reaction times, spatial awareness, and ability to interpret complex dynamic situations instantaneously. If you've ever taught a teen to drive you know. LOL.
So, back to my first statement:
...are people going to engage it "so that they are safer" or are they going to engage it in order to offload some of the stress of driving.
If you purposefully engage it to improve your safety, and are willing to be vigilant and put the extra work in, then it will likely enhance your safety. It's like another pair of eyes monitoring the situation at all times. But if you are turning it on so you can relax a bit and trust it to mostly get you there with minimal effort from you, (as NoAP does today on freeways) then you are actually going to be LESS safe, and indeed with current v11 FSD, will certainly get in an accident.