Buying a CV G1 weakens Barbarossa by 4 artillery that could reach Moscow G6. No experienced players do this buy. That should tell you about the strength of it.
Experienced players buy two bombers and a sub on turn 1 right? What is barbarossa and how does a carrier on turn 1 weaken it by 4 artillery?
Barbarossa is the German invasion of USSR.
A CV costs 16 IPC. 4 artillery also costs 16IPC. If you buy the former, you can’t buy the later with those same 16IPC.
Some experienced players do the 2 bomber 1 sub buy. This is a good buy if you want to threaten sea lion and Barbarossa. If you don’t mind tipping your hand, a lot of players would buy 6 artillery 2 infantry. This is a good buy if you are happy to allow the German BB to die. I personally like the 1sub + 6art and retreat the damaged BB back to SZ112 from SZ111.