like engineers, radio operators and navigators - it won't be Big Bang - a gradual erosion is much more likely
eg start with an automatic system but 2 crew....
then it works so you drop one of the crew...
then it works so you drop the other crew............
that's what they 've done/are doing on the railways
"Evidence based Crew Levels"...................... by then people will be iusing auto cars/buses/trucks - it'll be an obvious change - and if it knocks £ 10 of a flight to NY or LA they'll all be for it