I kind of hope you're joking, but just in case you're not I'll explain.
Because if I make a mistake every 3000 hours of driving, that's a mistake every 5-10 years. I am allowed to continue driving by the law.
If Waymo makes a mistake every 6000 hours of driving, and drives 50,000 hours per year, that's 8 per year. Said system would be twice as safe as me but would pretty much immediately get suspended if it's treated as "one driver."
Because if I make a mistake every 3000 hours of driving, that's a mistake every 5-10 years. I am allowed to continue driving by the law.
If Waymo makes a mistake every 6000 hours of driving, and drives 50,000 hours per year, that's 8 per year. Said system would be twice as safe as me but would pretty much immediately get suspended if it's treated as "one driver."