Commercial aircraft operate between extremely well-equipped points, so there is really no reason that they have to carry their power generation actually on board — they could more easily be run on batteries that are swapped out between flights, or (as has been pointed out before), powered with conventional jet engines using synthetically-produced fuel. Successful and cheap FF will be a game changer, but it doesn’t have to be directly used to have that effect — no one is going to drive a FF-powered car, and there’s no real reason to use FF in jets. (It makes far more sense for vehicles like ships and submarines, where travel times are very long, and space, where refueling isn’t really much of an option.)
