The best fiber for custom modern rugs is by far wool . It is the strongest, most vibrant, and most resilient fiber to be walking on. A low quality wool rug will outlast the best synthetic fiber (nylon, acrylic, polyester, olefin) all day long.
Couldn’t agree more!! A good household balance for me is 80/20. 80% wool, 20% synthetic as it helps to hold its shape.