We are building huge carriers (huge for our country) and yet they will only ever deploy with a limited number of aircraft.
Assumptions change. Your assertion is based on an assumption.
Would it not have been better for us to have built the latest all singing, all dancing LHA type vessel with the latest F-35B's, attack helicopters, support helicopters and then have the military hardware along with the landing craft.
There was (and is) no requirement for that capability (we have LPD, LPH & LSDA). It also leaves "someone else" doing your AD.
There was and is a requirement to provide air defence, both over Fleet and overland in addition to providing Air to mud support.