There are a staggering number of varieties of plastics, and an insane number of uses for them that aren’t easily replicated with other known materials. Some of those plastics are much worse than others.
Plastic is not inherently “pollution.” That’s not to say that plastics don’t make up a significant amount of the world’s pollution, but like literally everything in life, it’s not as simple as a black-and-white.
If anyone can make it through a blockade to deliver food, it’s Davos Seaworth.
I hope it’s more than just onions though.