Even after adjusting, it does look like autopilot is slightly safer (although not a strong enough effect to say for sure). It doesn't appear to be worse, so good enough to allow it, IMHO.

I actually wonder if there's another effect: Drivers only eligible for beta FSD if they meet a super high safety score (which isn't a perfect metric, but probably better than nothing). That incentivizes good driving even when FSD not engaged. Of course, that's a recent thing and hasn't shown up in data.