They lie, of course. That isn’t the real reason. The West contributes less then 1% of all plastic waste that is in the ocean, with Asia and Africa contributing 99%.
I don’t believe that it going world wide all of a sudden is just coincidental.
What do you think the reason is?
American streets are full of litter, including straws and straw wrappers, paper, plastic bottles, cig butts, etc.