Every year, billions of vehicles worldwide shed an estimated 6 million tons of tire fragments. These tiny flakes of plastic, generated by the wear and tear of normal driving, eventually accumulate in the soil, in rivers and lakes, and even in our food. Researchers in South China recently found tire-derived chemicals in most human urine samples.
It has nothing to do with being “not profitable”; they couldn’t find a way to engineer the tires to not be unstable at speeds above 45mph. They sell airless tires commercially today, but it’s mostly for farm equipment that moves slowly.