The first tire the Scottish veterinarian and inventor John Boyd Dunlop designed for his son’s bicycle in 1887 was made of solid rubber.
Later on pneumatic tires were developed, the air inside by being a cushion that dampened the shocks of traveling over uneven surfaces, making the ride more comfortable and making the whole weight less.
Tires filled with specially designed interior fillings will give you the same ride quality as pneumatic tires, but are puncture proof
Solid rubber tires still exist for use e.g. on forklifts, lawnmowers, golf carts etc