Because 1) the question was not "if it's safer", 2) "safer" doesn't mean "safe", and 3) safety isn't the only concern. For example, a self-driving car could be

Because 1) the question was not "if it's safer", 2) "safer" doesn't mean "safe", and 3) safety isn't the only concern. For example, a self-driving car could be programmed to drive aggressively, not stopping at red lights, not giving way, etc. and this would be unfair to other road users, even if it was completely safe. Everybody who has a degree of intellegence understands this. You simply lack the intellectual stature to have this conversation, sorry.