The Helpful Stacker
You seem to constantly think Navies only require proper anti-air capable ships such as Type 45s, subs and supply ships to defend CVFs. Other Navies who do not have CVFs still have such ships and subs to defend and support their military/civil maritime fleets and their overseas commitments, etc. As has previously been pointed out elsewhere in this website, carriers do not constantly need lots of your so called “pickets” with them in peace time. They carry out other tasks both around this country and world-wide.
As has also previously been mentioned by others in this website, why does this island nation really need so many land based air defense and strike aircraft and yet have so few quality RN assets that are able to defend themselves properly outside of any meaningful RAF protection and support range? Yes carriers are expensive, but why does the RAF still need so many very expensive strike and air defense aircraft?
Furthermore, if there was a major crisis it would be much easier for the RAF to obtain even more new/second hand aircraft in a hurry than it would be for the RN to obtain any carriers, further anti-air capable ships, be able to crew them and learn how to operate them, etc. Europe has plenty of air defense and strike aircraft and the US also has plenty of such aircraft readily deployable if required. The RN has learnt in the past that it cannot always depend on the RAF and other nations for its protection and support. That is why it needs its own very capable floating airfield, aircraft and warships and not a mobile airfield for the RAF as you call!