Tires aren’t made exclusively of natural rubber, they contain synthetic polymers among other things.
Additionally, by vulcanizing the rubber, three-dimensional chemical bonds resembling those found in synthetic plastics are created to harden the material.
So the end product is not really “natural” or “rubber” anymore.
Is natural rubber a plastic?
Tires aren’t made exclusively of natural rubber, they contain synthetic polymers among other things.
Additionally, by vulcanizing the rubber, three-dimensional chemical bonds resembling those found in synthetic plastics are created to harden the material.
So the end product is not really “natural” or “rubber” anymore.
What’s the alternative? Basically all wheels use vulcanized treads.
Public transportation
Which uses tires.
Traaaaains