I doubt the officers of other navies want to see their roles reduced to airstrips and transports any more than the RN, even in the USN.
The AEGIS system may have some use as an anti-ballistic missile system (or perhaps an anti-satalleite system), but the T-45 can’t do that, and any proposed frigate will not be intended to do that either, which leaves us with its ‘classical’ navy roles, ASW (which can better be done with helicopter carriers with ASW helicopters, or other subs), AsuW (best done with helicopters or aircraft which can see over the horizon) or support for ground forces off a hostile coast (which helicopters and aircraft are much better at providing than that single 105mm or 155mm gun most frigates use or will use)...
Again, what is being left out is how you protect your aircraft/helicopter carriers. There’s not much point having carriers which don’t have dedicated defenses against the myriad of threats that an enemy can deploy. That’s the main reason why China waited more than a decade to field its carrier so it could build up a fleet of escorts, replenishment vessels and even rudimentary organic AEW systems. Of course, you can build up a mythical arsenal ship with sky-high costs and about the same risks.
You make some weird assumptions on how navies think-most militaries dont really many choices in clinging to pet themes. If governments see any validity in implementing the kind of steps you are talking about, they would have shoved it down the throat of most admirals.