2 Separate Blowouts on RV Yesterday. Learned Important Lesson on Tires

My neighbor gets his Class C RV out once every 2 years. I guess he needs new tires every 3rd trip. Why don't they make semi solid tires that will last 20 years? These tires have 80 psi in them anyway. It wont make them any harder? I got an idea...how about just renting them for an RV that never gets out?
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