Let's see

No minetrawlers, the four US had were scheduled to be scrapped earlier this year. So if there's even a single mine you're playing russian roulette with hundreds of people on board

Probably heaps of various anti ship missiles that have been squirreled away with ranges reaching from few nautical miles to few hundred, just for this exact scenario, please keep in mind that you only need one missile to get through to cause dozens if not hundreds of fatalities.

Unmanned naval drones of various kind, not exactly ultra-high tech in this day and age.

And then there's the guerrilla speedboat attacks which means more missiles

Did I mention that one ship has possibly hundreds of people on board? The political system of the US probably cannot tolerate a military mass casualty event of that scale and spectacle. It's therefore just too risky to get anywhere nearby with a ship so all US navy can do is just lob missiles from as far away as possible, while hoping that this whole mess ends before US runs out of standoff weapons. And between Ukraine, Yemen and now this, the armament stocks aren't probably looking too good considering the meager production numbers.

This isn't a military decision but more a public opinion one. Should an American ship take a hit, have casualties, become disabled, etc it would put immense pressure on the administration to settle/end the war, even though on a military objective level it makes a lot of sense. This is a reality of the instant informational world we live in.

Imagine the optics of a single destroyer/cruiser being on fire. It would shatter the myth of American naval power (some are arguing that this war already did that, which I tend to agree with).

Armchair here:

Its like the issue with the Vietnam war. You need 100% perfect security, or its not worth it. If you are only 98% successful, you arent going to have oil tankers or any cargo ships even attempting it. A single failure every 2 months was a massive waste of resources.

While Iran still has fire control, these ships can be hit by shore-launched anti-shipping missiles, one way drones of even old fashioned shelling. Their "navy" was never even a factor.

Too risky, and doesn't make sense from a cost-benefit perspective. Iran uses cheap and disposable weapons that are also effective. If you think about how much a single US ship costs, and the political price of US service members dying, I think the picture becomes clear.

It would take far more ships (ideally destroyers and frigates ) than we can muster to the gulf.

Also, it exposes the ships to easy attack in a constrained body of water

Also, the ships would need to exit the gulf and travel a long distance to re-arm their defensive weapons, requiring even more ships.

Not wanting to lose USN ships as a de facto mercenary force is reason enough.

You could hit anything going through the straight with artillery and rockets from the shore. Escort won't do much.