a) We don't, and are just building them because it makes the Pentagun go starry-eyed, and we really, really luv the Pentagun.
Why would there be any more than this?
The one thing the military hardware types are reliably bad at is strategy. There's very little evidence that they have even basic strategic skills and plenty of evidence that they make bad, stupid and expensive decisions.
These carriers are being built primarily for symbolic and political reasons, not strategic ones.
The fact that other countries have fought differently in conflicts since hasnt altered strategy because they havent been "serious" opponents Any idiot can face a crisis - it's day to day living that wears you out.
The US navy is configured to fight a modern equivalent of the Japanese Soviet Navy, whereas European navies are mainly configured to fight Nazi Communist Submarine fleets.
But it was written as intended, no correction needed. "Re-fighting the last war" is often the last Great Power hot-war, and there wasn't anything in the Korean War or the Second Indochinese War to knock the Navy out of re-fight WWII mode. I've been accused of being a Marxist, yet while Harpo's my favourite, it's Groucho I'm always quoting. Odd, that.