Why? Polyester (as one plastic based fiber) gets a lot of flack because low quality clothes tend to use it, but polyester can be a fantastic fabric if done right. Durable, fast drying, and can be completely recycled.
For example, Patagonia tends to have high quality polyesters and has since the 70s. My experience with their fleece is that I can abuse it and it'll come out unaffected on the other end. Pilling now and then that I take down with a pill remover.
Nylon is also a fantastic material, when used appropriately, like for the shell of a jacket.
And don't get me wrong, cotton, wool, and hemp are all fantastic as well. Most of my clothing is those fabrics and they do a damn fine job at what they're good at.
"Polyesters" is a huge category. PET in plastic bottles is also a polyester, and it can persist for hundreds of years because it's typically in a highly crystalline form that resists fragmentation.
I was talking about polyester fibers. They have multiple orders of magnitude higher surface-area-to-weight ratio.
There are very few good studies of the degradation rate, and they typically focus on bulk products rather than particulates. So we have to rely on indirect evidence, the concentration of nanoplastics near polluted locations typically stays steady rather than keeps increasing. It means that it's in a dynamic equilibrium.
Another data point is lignin. It's a bilogical polymer, but that is not biodegradable in bulk, unless you are a fungus. And fungi don't have some neat enzymes that can degrade it, they just blast it with peroxides. And yes, there are lignin nanoparticles and you can detect them in water. These nanoparticles also don't accumulate and they can be degraded by bacteria because of their high surface area. Even though bacteria can NOT degrade bulk lignin.
For example, Patagonia tends to have high quality polyesters and has since the 70s. My experience with their fleece is that I can abuse it and it'll come out unaffected on the other end. Pilling now and then that I take down with a pill remover.
Nylon is also a fantastic material, when used appropriately, like for the shell of a jacket.
And don't get me wrong, cotton, wool, and hemp are all fantastic as well. Most of my clothing is those fabrics and they do a damn fine job at what they're good at.