Re: "Curbing their spread feels like a good idea"
That is true. But left alone, those big chunks of plastic will turn into microplastics over time. Another good point here is to avoid all the 'fast fashion' or 'ultrafast fashion' and instead buy some quality clothing that isn't made of plastic. Overall it will probably be cheaper over time as well.
A sidenote there: I run a lot, and use and obviously wash a lot of running/sports clothes. Over time I've found you can get woollen runing clothes, not just plastic-based ones. They're more comfortable, not necessarily any warmer than the other kind - and an unexpected bonus is that it doesn't smell like wet dog after every use. It seems to hold up better over time as well.