We still have to demonstrate that the choice to go cotton to avoid micro plastic release outweighs the tremendous water use that goes with cotton agriculture - water use that occurs in some of the most water scarce areas of the world.

And unless we're going organic consider the impacts of eutrophication and other chemical discharge/byproducts.

There isn't a silver bullet in material sustainability besides non-consumption. And we usually don't know (or agree) enough to weigh externalities against each other.

Its important that we study, assess, and (hopefully) mitigate the release/impact of micro plastics because their isn't a plausible path toward the textile product's industry to reduce it's carbon footprint in line with the UNFCCC without relying on recycled polyester.