They exist and are called "airless tires". Tannus is one of the most popular brands: https://tannusamerica.com/pages/tannus-airless-tires https://tannusamerica

They exist and are called "airless tires". Tannus is one of the most popular brands: https://tannusamerica.com/pages/tannus-airless-tires https://tannusamerica.com/pages/tannus-airless-tires They're solid foam and can't go flat. They're not very popular because they don't perform nearly as well as tires with tubes. They have a higher rolling resistance (ie, you have to pedal harder to go the same speed) and have a rougher ride. Good quality tires don't puncture that often and, for most riders, are worth the trade off.