It prevents the plastics from entering the environment. Plastics are a material with no effective bio-degredation process so we should destroy it rather than r

It prevents the plastics from entering the environment. Plastics are a material with no effective bio-degredation process so we should destroy it rather than return it to the environment. Otherwise we're just delaying cleanup. Incineration destroys these unnatural carbon chains and returns the materials to a state usable by natural life.