U.S. submarines sank a load of Japanese merchant shipping, but the lion share of warships were sunk by aircraft or shellfire.
The Japanese empire was uniquely vulnerable to submarine warfare, yet they would have never surrendered to a blockade. And those USAAC bombers would have never been able to to take off if their bases hadn't been taken by boots on the ground, delivered by surface strike groups. And WWII surface strike groups were nothing but targets without aircraft carriers.
War at sea requires command above and below the surface. Although the Japanese focused their submarines against our strikegroups, they failed to achieve much.
Of course CVs are vulnerable, forward operating bases always are, but its hard to imagine anything significant that submarines could do conventionally in any of the conflicts we've been in for the last 50 years.
Submarines launch Tomahawk Cruise Missiles and they can deliver SEAL Teams. They can also conduct espionage.