Most western countries have proper regulation regarding waste disposal. Plastic pollution is a big is a big issue, but wont be solved while big economies decide to export their waste to places with less strict regulations. This is - in my opinion - the point that needs pressure from conscious citizens.

We are only now starting to measure up the microplastics impact and their origin. Switching to reusable cups is a drop in the ocean, when tons of the stuff is released by simply washing clothes or makeup off your face.