Car and light truck tires are apparently only about 19% rubber.[1] More than half of a tire's composition is synthetic polymers, fillers, and textiles (e.g. polyester, rayon, nylon).

[1] https://www.ustires.org/whats-tire-0

Tires generate more particles of pollution than exhaust.[2] EVs are good. But eliminating car exhaust apparently isn't the big car pollution problem.

[2] https://www.theguardian.com/environment/2022/jun/03/car-tyre...