Also steel is 100% recyclable. If I recall correctly, most steel used today is recycled.

Most steel in the US and Europe is recycled. I believe most steel in China and to a larger extent Asia comes out of a giant pit in Australia.

https://en.wikipedia.org/wiki/Yandicoogina_mine

That mine runs fully automated ore trucks and the owner Rio Tinto wants to automate the rest. 950 ppl produce 18% of the world's iron ore from that pit.

https://www.abc.net.au/news/2015-10-18/rio-tinto-opens-world...

If this has 100x less carbon footprint and steel is 90% recycled, the polymer still wins overall.

Not in 10,000 years when it is still blowing around..

Current steel production is pretty awful too - radioactive materials in atmosphere via coal, leachates from additives, etc.

Microplastics haven't been proven to have much damage other than triggering karentils (karen's on lentil spectrum).

It's possible the strength could reduce microplastics?

Or increase the risk posed by microplastics.

Very tiny, very sharp flakes of very strong materials could be asbestos 2.0

I imagine that even things that are nominally strong might be susceptible to things like UV. But IANAC.