It takes us nine years to build one carrier - and there’s only one shipyard that can do it.
Compare that to 1942-43, when we built and launched almost 100 carriers of various types.
On top of that, we already had several designs on the books for carriers that could be quickly mass produced. Among many other classes.
As it is now, we dumped all our eggs in the LCS design basket and since that turned out to be a massive failure, we’re having to address our desperate need for seagoing designs by buying other countries’ off the shelf frigate designs (because we don’t have any frigate designs ready to go and it would take most of the decade before we did.) We also don’t have a viable alternative to the cancelled Zumwalt class. Which doesn’t have a working main gun.