If I may, Gullwings, let me point out that it is not a question of what the Navy needs but what UK needs.
Carriers are but one way of projecting power worldwide - they are slow to get there and they need protection. Land based air can often get there quicker and operate from secure bases close enough. But not always and that is why the carriers might come in handy.
However, can our piddly little economy support the projection of power (power we don't have) worldwide.
No - we cannot and our politicians had better get used to the idea. They are subservient even to Brussels let alone the rest of the major nations.