I’m lumping things like Tesla FSD.

But also, there are explicitly times and areas where Cruises don’t operate due to being insufficiently able to operate. And times where they do just pull over and wait for human intervention when they don’t know what else to do. Both of which are safe and reasonable, but which also selects themselves into a safer set of miles actually traveled.

Human drivers "disengage" also, though we don't think of it that way. I have aging friends who refuse to drive at night. I'll stay home in bad weather. When I was younger, I'd sometimes ask a passenger to back out of tricky parking space for me.

Yes, but we’re still comparing a highly selected set of AV miles vs the massive variety of human-driven miles.