I apologize I came across as offensive. I wasn't going for that. I believe the key to beating carriers, if you don't have them, is in ship roles. As those who have been playing for months can see GC3 is not a rock, paper, scissors type of combat. A fleet without a carrier of it's own would have to operate differently to win than if it was fighting only battleships and cruisers. It is expected battleships, and all ships, are at a very bad disadvantage against multiple fighters launched from a carrier. The best way to counter a carrier is with another carrier.
Edited: Think about GC2. NO carriers in the game. But one of the best ways to win was to increase your logistic tech and have a glob of smaller ships with multiple weapons attacking a smaller group of larger ships that were more powerful. Doing what carriers do is a very good strategy. An idea to counter carriers if you don't have them is to design support ships that have lots of missile weapons. Your whole fleet doesn't need to be full of support ships but these support ships should also be affected by augments that increase missile range, damage, and accuracy. You will eat at the enemy fighters. Unless of course they are beefed up in point defense. In which case we are back at countering carriers with carriers.
It all comes back to your lack of first-hand experience. You're speaking purely hypothetically, without knowledge of how the mechanics actually play out in-game. You will not "eat the enemy fighters" because there are too many of them, and your ships, however numerous, simply can't take them out quickly enough to make a real impact. Even you throw a fleet at some carriers, it won't matter because the fighters respawn immediately.
However, much of the discussion is not focused on "beating" carriers - but rather using carriers. Fleets of carriers make the game too easy (and would even if the AI could make strategically designed fleets) - thus I don't use them at all - and really, mechanics like this are the reason I hardly play anymore. Nothing feels balanced, so nothing is ever fun.