But let's assume that somehow the UK gets into an "us and nobody else"
conflict. Offhand, I can only imagine the Falklands or maybe Gibraltar,
neither
of which is very likely. Gib could benefit from land-based air, so let's
assume

I agree 100% with your general sentiment. The F-22 is bloody brilliant.
Period. But when is the last time that A-A was a serious threat? 1980
Israel-Lebanon/Syria? That's 26 years ago! Now there are very few
countries that can afford the top cover (radar) and training that go along
with NATOs forces. And it's very rare for NATO countries to go alone (even
the US operates with allies most of the time). So what's the urgent need
for fleet fighter air defense for the RN? Sure, it'd be nice to have. But
it would be nice to have naval versions of the F-22, with pilots who fly 5
hours a day, as many days as they can. But you have to balance cost vs.
reward, and I think the low-tech, low-end threat is a much more serious
problem to the RN than worrying about aerial attack (with all due respect to
Murphy and his laws). At least, that's my two cents.