Why a six-carrier fleet can support its own aircraft

Would a British naval superpower still have to buy an American carrier fighter such as the F-14?

Not if it operated roughly six or more carriers, enough to justify a national carrier-aircraft programme.

Aircraft independence depends on the size of the carrier force that will buy and sustain the type. A superpower operating six or more carriers can spread design, testing, production, training, and support costs across enough air groups to justify a domestic programme. A smaller fleet usually lacks that economic base and must share or import aircraft, unless the state accepts unusually high costs. France is noted as an exceptional case willing to sustain national designs for a single-carrier force.