This definitely feels like a very hopeful and intentionally narrow sited analysis. Like, we're saying that Waymo's accidents were primarily low-speed collisions but also they were only allowed to go 35mph max and drive in off peak hours when accidents are far less likely to begin with. If we're doing a comparative analysis then we'd need to compare to humans driving unimpaired during off hours at 35mph at most. And, it's also definitely worth considering how predictable and consistent the failures are; a human might miss someone backing out and hit them once because they are distracted. A computer missing the same means that there's a set of conditions that will trigger failure every single time they occur. So, if those conditions are repeated heavily in any place then the likelihood of catastrophic failure increases substantially.