Reinforced concrete is almost two hundred years old by now [0]. How many people live in homes built over one hundred years ago? Not only have many of those old homes been replaced, but the population is much larger now.
the arch is almost 2500 years old now, and although you do normally use timber beams (or bamboo) to build one, they aren't part of the final structure
vaults, domes, and flying buttresses extend the arch principle to enclose large spaces. there are domes still standing made from unreinforced concrete that are 2000 years old
Reinforced concrete is almost two hundred years old by now [0]. How many people live in homes built over one hundred years ago? Not only have many of those old homes been replaced, but the population is much larger now.
[0] https://en.wikipedia.org/wiki/Reinforced_concrete#History