There is no way they can block off the straight and hold off the USN. They have no peer adversary.
Warships have existed for thousands of years and I expect they will continue to evolve for perhaps a thousand more.
13 Japanese aircraft carriers and 7 Americans aircraft carriers lay at the bottom of the pacific from WW2. Yet they have been replaced and improved.
One of those 13 Japanese carriers was actually a submarine that could launch planes.
https://youtu.be/-1AJurcSWCw?feature=shared&t=1308
You are at odds with US intel and all interested parties in that view, David. Iran are unlikely to do so but the capability to close it isn't really disputed. I expect naval power will evolve in some ways, probably some form of unmanned drones, but Aircraft Carrier strike groups are already becoming neutralised. The Yemenis (AnsarAllah) caused so many problems that they forced a number of Carrier Groups to retreat. Iran's anti shipping capabilities are magnitudes greater than AnsarAllah. The counter measures to Carrier Groups are akin to artillery versus cavalry charges and have made them redundant already in any serious war. There are anyway a multitude of ways to close the Strait of Hormuz. Mines, marine drones for starters would close the Strait to commercial shipping. How would US navy operating in the narrow confines of the SoH be able to tackle even the above without being targets themselves? Iran are playing a "home game" David and this is the most relevant factor.
It is generally accepted, even by US intel, that Iran could close the Strait. It is a card that Iran holds that impacts on all other decisions in the attempts to subdue Iran. US navy couldn't prevent the closure, David. Iran don't need to be a "peer adversary" in naval power to close Strait of Hormuz.