Bubbleheads think the surface Navy is going to act the same in peacetime as war time. In a wartime a CVBG is not going to go into a high probability area-ever. It will be the primary job of the sub fleet to track and contain the enemy sub fleet.
Back to the laughable peacetime sub exercises. The attack sub stars out within 10 miles of the CVBG Well they have already won before the exercises starts. Put that sub 200 miles away and let the game start. See the difference then. Additionally a modern carrier is almost impossible to actually sink. They are durable and repairable. Designed that way.
Recently the Navy had target practice on a FFG 7 class and it floated for 12 hours after taking 2 mk48 hits. A carrier would have been taken out of action for sure and would have needed dry dock but it would have been repaired easily.
I saw that video of the frigate. If it had fuel, it probably would have caught on fire.
I pretty certain a submarine can sink a carrier. It would take a few torpedoes. At a minimum, it would be able to disable it.
Submarines can sit at choke points and wait. In places such as the gate of tears or the straight of hormuz.
One thing I would say, is that a couple of times we were found by a platform a lot less advance than a US warship, and they were not even looking for us.