Washed up waste is the tail end, the only "big" difference it makes is to the localized beach until the next tide/current comes from the source of the pollution.
Saving the monitor, releasing the diy reduces a (minor) head end of the problem that is not only leading to long waste in a landfill, but also metals and plastics in water.
If everyone spent 2 hours a year removing washed up waste from the beaches, it would have made a big difference.