This is a fine argument against banning plastics. This is unrelated to "Microplastics Moral Panic is a textbook study of F.U.D." though.
If microplastics are a case of FUD, then there's nothing to look into. How and why would anyone discover anything surrounding a case of moral panic/FUD? By definition, there's nothing to discover.
Discover what plastic is harmful and we can't start to talk.