There are so many options - STOL aircraft, even planes modified for water landing/ takeoff. Perhaps a fighter could be carried up in a "cradle" that would look like a huge rocket man pack, but that would leave the difficulty of landing. The reality is that a sub carrier WOULD be possible.
After all, even a bog standard carrier, for all its limitations, isnt exactly cheap.
Stealthy carriers could mean huge savings in other areas.
I remember reading about submersible carriers and thinking that was pretty stupid.
The primary role of the carrier is to provide eyes and ears and a fist on the end of a very long arm and a carrier can't do that while submerged.
I remember a game called Interceptor, by Bob Dinnerman that had Mig-29s (black coloured F-16s) that operated from a submersible carrier.
The thing is that subs are not invulnerable either and a submersed carrier is not useful as a carrier till it surfaces and launches aircraft.
STOVL and other carriers are expensive and their aircraft are expensive. Submersible carriers would be very expensive too.
CTOL carriers offer cheaper aircraft with better compatibility with land based aircraft... the problems that need to be solved is how to pack lots of aircraft in a very small space in a way that they are fully usable yet you can carry enormous numbers in the smallest possible ship in terms of weight.
Bigger heavier ships are expensive ships... but at the end of the day you get what you pay for. No one will tell you that 20 Corvettes are better than a Cruiser because each of those Corvettes are more vulnerable because of their small size. They will lack radar range and power, and they wont pack the same punch as a much larger vessel.
They serve a purpose but at the end of the day a bigger ship is safer all things considered.
Nothing is invincible, but thinking carriers are big slow targets is like saying AWACS aircraft are big slow targets. The reality is that they provide a capability that makes them worth having and integrating them into your force structure means they are as protected as any other component... often their presence makes everything better protected.
A Nimitz class has ....at best.... 4 air-worthy E-2 at anytime, this mean that....at best....2 of them could be used contemporaneously for area reconnaisance missions (and naturally at this rate several hours at day will be totally devoid of airborne sensor coverage !!).
But we are not talking about American carriers... by 2025 the main fighter on the new Russian carriers will be PAK FAs... likely each with their own 360 degree radar sensor suite. The dedicated AWACS platform might be a UAV designed to fly for days, or it could even be an aerostat that can be towed by a frigate or destroyer...
How anyone can easily realize, at worsen furtherly the picture, none of those relations are linear....
Except that for most of the time Russia will have satellite coverage as well, so the AEW aircraft can be directed to where activity has already been detected to get a better look, or to decoy the enemy into thinking you are somewhere you are not...
Cold war era Kh-22M has an effective engagement range ,when delivered at high altitude by supersonic TU-22M3, greater than 550 km .
But the problem remains... which countries have supersonic bombers delivering rather large supersonic anti ship missiles? Right now... not many.
More importantly how would a Russian naval group be any safer without a carrier... most of the time it will be AEW aircraft from the carrier that detect threats first, so remove the carrier and you strip away that vision.
Also even Mig-29Ks will be carrying RVV-BDs with a flight range of up to 280km, so in many ways they will be more like F-14s with Phoneix missiles than Hornets with AMRAAMs.
"Aegis" can receive informations by external assets (land/sea/air/space based) but none of them is a part of Aegis Combat System .
ACS is designed to opearate totally authonomously in a very precise and compartmentalized way, founded on the basis of well defined ellipse of integrated systems the two focus of which are AN/SPY-1 radar and SM-3 missile
Russia doesn't have AEGIS, it has Sigma, which combines data from a range of platforms and sources both within the surface group and also submarines and satellites, and aircraft.