There are a whole lot of things wrong with carrier aircraft, and how they interact with the rest of the game.
Carrier CAS being largely a waste of time is only part of it.
There is little point in building Carrier CAS to be used in an anti-shipping role, because carrier NAV are more effective at sinking any and all enemy ships.
Carrier CAS can be used to support naval invasions, but involve a great deal of micromanagement to achieve this (parking the carriers in a zone close enough, assigning the air wings etc), and afaik this can't be automated (unlike ships assigned to shore bombardment duty).
As standard, the AI will only build carrier fighters & carrier NAV on newly-constructed carriers. Only a handful of ships owned by AI countries will ever have CAS on them, (a few of Japan and the USA's starting carriers).
The air wing composition should be affected by naval doctrine, but it is not. There is no ingame way to change composition for AI countries, only by changing definitions and equipment files outside of the game.
Carrier dive bombers & torpedo bombers, should have different attack abilities, esp. against different kinds of ship, but they do not. All air attacks ignore armour, which means that tech developments such as better torpedoes (or even having torpedoes in the first place), isn't an option, and neither are AP bombs.
So there's no difference, except in amount of damage, between a dive bomber that can only carry relatively small bombs, and the torpedo bombers that dropped torpedoes, or large bombs.
Dive bombers equipped with bombs & rockets should be more efficient at convoy and small ship attacks, whereas you'd prefer Torpedo Bombers to attack heavy warships. As an example.
Carrier aircraft cannot attack land targets - which was one of the planned objectives of the Pearl Harbor Raid - to attack the oil tanks and repair facilities, making the port unusable by the US Navy. This wasn't done in history, but in HOI4, it's not even possible.
I've got some ideas about how it might be possible right now to change a few of these things though, need to experiment.