These arguments surface all the time. You do not need a carrier to provide air defense for your cruisers. It's the other way around. You can provide air defense with area defense missiles quite a bit more cost effectively than with 24/7 CAP, especially in the case of the Russian carriers which have very limited fixed wing assets.
25 years ago SAM's hardly reached 100km distance, and even that against high-flying targets. Morever, how you would support Tu-22M/Tu95 AShM's attack against enemy CBG without own carriers? Even now, when ship's SAM's range reached 200+ km - it is still much closer than 800+ km for range for SU-33, and again doesnt work that well again low-flying targets.
BTW, Kuznecov have airborne EW - in form of Ka-xx helos.
Sure you can keep the fighters at ready 5 or ready 15, however your area AAW defense system will react quite a bit faster than sending the alert aircraft aloft.
Lets assume possible enemy aircrafts attack is detected 400-500km away - pretty realistic scenario in case of really massive attack. Current USA naval strike aircrafts do not really have enough fuel to make supersonic approach all the way, so they will most likely approach just below 1M speed. That would give 20-30m reaction time for aircrew - more than enough to launch ALL Su-33 from Kuznecov. Even in case of supersonic approach (1.7M) there is still about 10-15 min warning time.
Why would you use carrier fixed wing assets for bomber escort? Bombers should have their own land based escort. You also pull away your fixed wing air defense assets to protect your carrier.
Because the range of Tu-95M is 8.000+ km. The range of Tu-22M - 2500-3000 even without inflight refueling. Find me a possible escort fighter...
Aircraft carriers are for power projection. Why spend all that money otherwise?
Because even limited force projection is better than none.