I've been trying to get 100% natural materials (cotton, wool, leather) and they seem more comfortable, less stuffy (especially for sleeping) but that might be a placebo.
I imagine most people don't think about their plastic fabrics being plastic at all, they really don't feel like plastic. So when you see lint balls or bits of lint floating about the house you don't think to yourself "Ah, little bits of plastic going into my lungs". When you empty the lint catcher in a drier and pop it right in the bin, it probably doesn't cross most minds that it's a little bundle of plastic fibers. I like to consider myself pretty well informed on the topic and it wasn't until this year that clothing fibers even crossed my mind.
One morning it occurred to me that I've been flushing microplastics away, which is really terrible...
Catching particles coming from the wash seems like a pretty tough problem. Even if the washing machine could somehow catch these, I can't see consumers (and thus manufacturers) jumping at the chance to clean out dirty soapy goop from a washing machine filter... which I imagine will resemble cleaning out a shower drain trap pretty quickly.
Natural materials are obviously more comfortable, more breathable, hypoallergenic, etc. These fabrics are literally the product of millions of years of evolution for putting on top of an animal's skin, and work well with its physiology.
There's of course significant processing applied to those materials before they're suitable as clothing (cotton obviously needs to be picked, it's not on an animal to begin with; leather needs to be tanned).
Huh? They're obviously optimized for regulating the temperature of the animal they came from. Except for cotton and linen. And they weren't woven. Viscose is pretty comfortable, but it's not a natural fiber. Fiber blends are pretty amazing, too. There's some interesting properties you can get with blends.