Human drivers can adapt to a new unseen before situation.
On the other hand, software can make mistakes at scale whereas each human makes mistakes differently.
It’s not so cut and dry.
The same kind of trade off happens with other modes of transport with very rigid constraints on movement, things like trains. A train can keep going, stop, or maybe with enough time reverse if there's tons of time and a strong need.
We don't stand around worrying saying "BUT WHAT IF SOMETHING'S ON THE TRACKS?!?", because the answer is "well then, the train will hit it. That's the tradeoff for being able to move freight so efficiently."