Why can't the chainless bicycle invented by a girl of 2 1 year old in China be popularized?

The chainless bicycle invented by a 2 1 year-old girl in China cannot be popularized because of its high price. Chainless bicycles are mainly expensive, difficult to manufacture and not popular. The price is several times that of ordinary bicycles, which is unacceptable to ordinary people. Chainless bicycles use two pairs of figure-eight wheels.