With respect... I'm not sure you have a complete understanding of Naval Warfare and Amphibious assualts. Being a resident Marine, and having deployed via a naval vessel as my taxi.... I can assure you that if you dont see the significance of the aircraft carrier being rendered obsolete due to lack of defenses agains surface to ship missels.... you're missing the boat.
Until 2016 and Houthi's shot at some american ships (you can find the story on fox news... its not exactly what happened, but the gist is close enough) The US navy didn't know if the CWIS even worked against incoming regualr surface to ship missles. Now a hypersonic missle? Zero defense that we have seen tested on this.
I am sure the 1000 lb brains at DARPA are working on a countermeasure... but so far nothing seems to be presented.
Here's the thing.
Lets accept your postulation that submarines are going to hit multiple surafce to ship missle sites that fire hypersonic missles. Subs are fine to sink other subs/ships. At a certain point, war has to transition from naval to land if we are talking about maintainig a foothold on a piece of land. You cant put boots on the deck from a sub.
They are a compliement to the Naval Fleet. Not the end all be all however.
You only need 1 or 2 missles to hit an aircraft carrier. It is not possible to shoot all of them down. How many air craft carriers is the US going to sacrifice for Tiawan? 1? 2? 5?
Do you honestly think we have intel such that we can identify every launcher site? No I dont. More likeley we are going to identify this after the launch by finding radar signatures at the POO site (Point of Origin) . I'm not going to get too indepth on all that here for obvious reasons, but all China would have to do is turn off their radar at launch sites until right before launch. The kill chain loop is too fast to identify and kill these targets in a matter of minutes from a submarine.
Youre also assuming that China wouldn't have sophisticated ADA / Anti Air defenses such as S-300 or S-400's with radars on during times of launch. When we shot multiple Tomahawks from Subs against Syria in the 2017-2018 timeframe, it was the JASSM-ER missles that were launched from B1's which actually struck the target.... Not the tomahawks.
JASSM, used in the attack on Syria's chemical weapons cache, can strike targets with pinpoint precision from hundreds of miles away.
www.popularmechanics.com
The April 14 (local time) US, UK, and French strike on Syrian chemical weapons research and storage facilities marked the first combat use of the AGM-158B Joint Air-to-Surface Standoff Missile-Extended Range, according to the Pentagon.
www.airandspaceforces.com
You have to put boots on the deck to maintain any foothold on a peice of land. The air craft carrier is the equipment that does that. Unless you think we are going to fly all our troops into a neighboring country whom would allow this... but who is going to let us land and then launch an attack against China from bases we already have a presence.
Japan? South Korea?
The Tiawan conflict is simply not one The US is set up for success with.
Island Hopping style campaigns... which is something the Marine Corps is resturctured around, is one thing.... but placing boots on the deck on Taiwan at the threat of hypersonic missles when China is committed to mainting a 1 China Policy (something we originally recongized under Nixon) aint a thing.