I also disagree sharply that plastics are not caring about other people, because the idea is circular – you’re starting with the idea that we can harm the world with things other than aveiros, i.e..plastics, then proceed to say that it’s spiritual because it’s hurting others….which is only true if you accept first that it is actually hurting others. And to do that you need the global, theoretical investigation level which we don’t have a source for.
I know of no gadol who limits their use of plastics. Do you? Are all of the gedolei yisroel guilty of not caring about others by using plastics? Sorry, but I don’t see anything convincing here.
As for localized pollutants – see above, it’s a good point.