Except that that is self-evidently false, and we're not talking about some meaningless argument in a vacuum, but one between humans who have experience of the world.

It's fairly obvious that things like pedestrian detection systems with automatic braking, lane departure warnings, tiredness detection, etc. will make a significant difference as they become widespread. These exist in production today and similar technologies are in active development and deployment.

There is no reason to believe that human driven cars can't be made safe through technology without requiring self-driving. There may be other benefits to self-driving cars that are desirable, but as I said, the road deaths argument is clearly just fear mongering based on the false idea that other technological safety measures are not being developed.

As for costs and numbers - those certainly aren't provided by self driving car advocates, who can't even say when the technology will be available or how basic legal and economic problems it presents will be overcome.