The worst outcome possible
Following the damning report on the F35, and the truly horrifying cost overruns, what if tht US decided to can the whole thing. Those of a certain age will remember the TSR2 F111 debacle. An incomming Labour government cancelled the TSR2 project on the promise of cheap and better F111s. The TSR2 project was not only cancelled, but all the design dat was destryed, all the jigs were destroyed, all completer aricraft, part completed an parts were destroyed utterly. They were burned. Then - the F111 was cancelled.
Move forward 40 odd years and what if the F35 gets the chop. The US can survive withouit it. The Marines would like it, but not essential. The Navy Has both better and cheaper alternatives. Where does that leave thE UK. Both carriers are nearly useless without the F35. Extend the takeoff area and non STOVOL could takeoff, but without an angled flight deck there is no feasable way they could be recovered. The entire deck would have to be cleared to recover a plane. The reason the US won at Midway was because the |Japanese carriers, sorry I foret the names, had cleared their decks to recover planes, so were defenceless when the US attacked.
But wait, it gets worse. As I have mentioned before, without a catapult launcer the carrier has no long endurance AWACS. A carrier group without AWACS is just target practise.