You're cherry-picking plastics here. The same can be said about just about any technology developed in the past 200 years, so what makes plastics special? We laugh at people who talk about the "precautionary principle" for vaccines or cling onto dubious research that purports to show some ill effects. Or, how about applying the precautionary principle to air travel - after all, do we really know the effects on your body of frequently changing timezones?

We've been using plastics for a long time. They improved the world in important ways. There's nothing we can detect in large-scale studies of industry workers or other exposed groups that would suggest they're dangerous. That's kind of it. Every story you see on HN about microplastics is hand-wavy and involves dubious assertions and hypotheticals, and the alternative is... what? That we go back to making all commodity items out of metal, with a more serious environmental impact, higher transportation costs, and so on?

There are wasteful uses of plastic which should be curtailed, e.g. for packaging fresh produce - but the concern here isn't microplastics, just pointless trash.