China, Indonesia, Philippines, Thailand, and Vietnam dump more plastics into the ocean than all other countries combined. That's because these countries have large numbers of people in poverty or under economic or political stress, who typically are far more concerned with the immediate needs of survival than with hypothetical environmental concerns.
What makes it worse is that the garbage doesn't all come from those countries... a good part of it comes from industrialized western nations because those nations find it cheap to make their trash someone else's problem.
The reason this isn't discussed is that fixing the issue would require the wealthy western nations to intervene economically in those places to change the situation, something which would be resisted by the governments who find advantage in having a population that's not educated and remains under stress.
On top of that, climate change is happening.. those countries and people are going to be under more stress soon, not less... what will happen if, one day, those people have a choice between surviving another year by dumping toxins into the environment that will sterilize the oceans or dying?