SAS, I don't find your ojection to OTH credible.
OTH capability is a good thing to have if you intend to conduct sea borne raids or initial combat operations of a larger phased operation.
Part of the reason it is good capability to have is the element of uncertainty it raises in the minds of (thus prep for a fight), any adversary.
Fast forward 20 years from now.
More and more places and people will have available:
Drones used for surveillance
Access to satellite imagery
This makes detection of an amphib flotilla more likely.
That won't change how OTH is effective, but it will change where in the battle plan, and operational phasing,
the anti drone effort takes place
the anti satellite operations take place.
As an analogue, look at SEAD: suppression of enemy air defense. Look at how that was done in Bosnia, 1995, USS Normandy, Desert Storm, using Apaches, and versus Iraq 2003.
Likewise with the eyes of your enemy in any future operation.
Screw his ISR plan to help you operation be less predictable.
If you intend to project power, which US strategic doctrine tends to be about, see the OCEANS, you still need to get your fighting forces ashore, in a timely fashion.
If timeliness isn't important, the USMC would still be using that inexpensive Higgins Boat.
