As others have said, the US can “reopen” the straight at any time they want. It’s not an issue of capabilities. But it’s very resource intensive and very expensive.
The logistics of escorting ships in and out of the straight isn’t trivial. I forget the name of the operation, but they did implement it for a few days before shutting it down. Politically, I imagine it’s pretty hard to justify the cost /benefit
On the Iranian side it takes a very small amount of resources and logistics. All they have to do is project power, whether they have it or not, and the shipping & insurance industries have to respect it.
Drones are really cheap, and that’s about all it takes for Iran to leverage their influence over the straight. Which is kind of crazy when you think about it. But it’s about the only bargaining chip they have left and they aren’t going let go of it easily.