I apologize in advance for the armchair engineering, but from a basic knowledge of material science, everlasting tires probably aren't practical. The tire needs

I apologize in advance for the armchair engineering, but from a basic knowledge of material science, everlasting tires probably aren't practical. The tire needs to be soft and grippy in order to be safe on the road. Soft things will be worn down by harder things. So to keep the tire soft enough to be safe, you would need to add more material. But lots of mass on the outer circumference of a wheel would have negative implications for performance and fuel efficiency. And besides, modern tires last 50k miles. That's twice around the planet by friction force. That's not enough of an engineering marvel for you folks?