The original comment was talking about cleanup costs. You realistically can not clean up shed microplastics. A fleece jacket sheds millions of them every wash as well as just wearing it. How are you meant to collect all of those microplastics that just blew off in to the air.
So just a blanket "Charge everything based on it's cleanup costs" doesn't work.
Same way you do asbestos remediation. Enclose the area, filter the air, create a clean room around the entire area.
Maybe in the future you laser-atomize every spec that floats past the actor inside an 8ft cube. Who knows?
I don't think it'd be practical to switch overnight - much of our societal infrastructure needs re-engineering for sustainability which will take time - perhaps a gradually increasing percentage of externalized costs can be integrated over time. It'd be real progress toward a Venus Project style resource based economy.
So just a blanket "Charge everything based on it's cleanup costs" doesn't work.