Do discarded fishing nets really cause more harm to fish than actively used ones? The whole job of fishermen is to kill fish. How can you say they're environmen

Do discarded fishing nets really cause more harm to fish than actively used ones? The whole job of fishermen is to kill fish. How can you say they're environmentally responsible for not losing their nets? The environmental problems caused by fishing already exist and are far more severe than those caused by plastic which so far are mostly only theoretical or imaginary. The UN says that "half the world's fishing fleet could be scrapped with no change in catch." That's how much overfishing they're doing. It's not environmentally responsible.