In the 1980s, in the Persian Gulf, Iran deployed North Korean sea mines against Iraq (and probably American) naval forces. Guided missile frigate, USS Samuel B. Roberts (FFG-58), struck one in 1998.
The World War I Era technology mines were so old, they became new again. The US navy had to get re-acquainted with mine sweeping on the fly.
The true value of sea mines is that they cause enemy delay and enemy expenditure of resources. They can be one more cut to bleed the enemy of time, materiel, and personnel in a war of attrition.