I agree these numbers only argue for human+computer vs human, and not computer vs human.

I'm curious why you think the benchmark should be computer vs human, though. Autopilot is very clearly a human+computer system; it states you need to be alert, and it forces you to keep your hands on the wheel and apply wheel torque occasionally to make sure you're actually paying attention. Why would Tesla benchmark something they don't ship (and how could they even do that)? The question for the general public, and for Tesla owners, is whether the current system is safe. It appears to be.