I have made plenty of 1/350 kits all of the following with photo etch added.
USS enterprise with full air wing, hangar interior and interior lighting, Likwise Nimitz. Also Bismark, Missouri, Yamato, Prince of Wales.
Whilst large carriers obviously contain plenty of plastic, they do not contain many parts in their basic form. They are far simpler in construction. A look at the spruces of either of my carriers would show this. The most numerous parts are probably the much duplicated life raft boxes.
Airwings cost a fortune if you take that route, with the kits, the photo etch and then the individual, unique aircraft markings. You can have as few or as many as you like. A sparse hangar deck would suit many (although I went the whole hog throughout with interior walls, fire door, double skins at lift apertures etc etc). Total cost for Nimitz would be Kit £140, Etch £120, Aircraft £70, Decals deck and aircraft £70, LED lighting £20, Hangar parts from plastic sheet, spares box etc £5... Total £425. Model making ain't cheap. I would upload some images, but the site won't allow them from my iPad.
An HMS QE would not in my opinion be any more difficult to produce (with just a hangar deck inside and no walls etc), than an Illustrious. Improving it with PE would be covered by Lion Roar, Ensign, Toms or similar. There are only 2 aircraft types, F35B and Merlin ASW and AEW fit (one extra part).. around 50 at most. The rest would be down to the doubtless grateful modeller.