Single pilot crews may well be one reason why the RAF Bomber Command had operational loss rates comparable with or higher than the USAAF did. Plenty of B-17s and B-24s returned with one pilot dead or incapacitated. I have flown many flights where one of us recognized a threat the other didn’t thus validating the TWO pilot crew concept. I think two pilots is a floor below which we descend at our peril. And NEVER buy a ticket to ride on a drone!