Cheap drones are only effective against relatively soft targets. Weak penetration and small warheads limit their utility.

Many countries already have long-range drones designed to attack ships i.e. anti-ship missiles. They cost $1-2M a piece. It would still require a minimum of many direct hits to sink a modern aircraft carrier, as commonly demonstrated for SINKEX.

How would a drone sink a carrier? If Iran could do that they would already have sunk the American carriers.

The risk at the straights aren't drones but torpedoes and mines and attack boats.