Even if the ships don't directly play a part in the Ukraine war, it makes things harder for Russia. They have to spend more resources guarding these ports now,

Even if the ships don't directly play a part in the Ukraine war, it makes things harder for Russia. They have to spend more resources guarding these ports now, far from the front. It brings the war back to Russians. It's a lot easier for Putin to hide the loss of thousands of troops in Ukraine than it is to hide a big ship getting sunk in a port in a Russian city.