Because we only started our reforms in 1978, it takes time to establish the proper science and innovation systems like abolishing unnecessary bureaucratic regulations, provide access to low cost capital to startups, lower taxes of businesses, develop consumer markets in every sector of every industry for companies to innovate and produce to earn revenues, develop deep and liquid financial markets to give the correct market signal to companies on whether they are succeeding or failing, allow the culture of risk taking and failure, allow market forces to determine the cost of land, labour, capital, energy, electricity, water, remove government meddling in micromanaging the economy and businesses, etc.
China is rapidly establishing all these mechanisms through reform to allow an environment for scientific discoveries and innovation to take place. 15 years is more than enough for China to match the US. Never underestimate the ability of China. US is nothing special. We can match them and eventually overtake them.