It is asymmetrical warfare. A hundred plus ships went through the straight daily. Attackers only need to occasionally damage a ship to make the crossing look deeply unappealing. No military intervention can promise 100% defense to passing vessels.
As the value of the oil goes up it becomes worth it to risk the ship. Even if you're paying to insure it there's an equilibrium point between odds and value.
Obviously 50-50 doesn't pencil out at $100 or even $200 a barrel. But 1:50 might at $2xx. IDK I'm not a shipping expert.
Whatever Iran wants is the cheapest course to resolution.