When you mention this, people reply we should set an example and other countries will follow. The idea that Western countries should set an example to teach those 'dumb countries that can't think for themselves' how to do things seems very arrogant. And there are zero guarantees it will work. If it was as easy as setting an example, every country on earth would be a blossoming democracy by now...
[0] https://www.nature.com/articles/ncomms15611#f1 [1] https://www2.mst.dk/Udgiv/publications/2018/02/978-87-93614-...
Edit: An actual solution would be if the EU invested in waste management solutions in the developing world.
People mention micro-plastics as a bad thing but we don't know that yet. So far the level of evidence proving micro-plastics as harmful is on par with the evidence linking cancer to cellphones.