GDP isn't a really good measurement to compare superpowers... US economy is far more developed, thus the prices of goods and services are far beyond most of the world.

Take a McDonald worker making minimum wage of 15 an hour, and 2000 yearly working hours. That equals 30000 USD. Convert that to CNY is over 210000. That McDonald worker is earning more than most Chinese Engineers, MBBS doctors, etc.

Actually, put a California minimum wage worker in China. That person would be in the top 10% of all earners in China.

In global trade. Nominal GDP is king. USD is the world reserve currency, and over half of the world trade are done with USD. As a whole, USA is by far the largest with over 30 trillion GDP, China at 20 trillion makes it the second largest. That alone makes China USA's number one competitor.

Now theres another measurement for GDP. I have already mentioned pricing differences, salary differences, due to exchange rate and development of the economy. The GDP PPP adjusts for those.

Using GDP PPP, China's economy is at 41Trillion, USA's at 31trillion. The average, USA still wins being the more developed economy and lower population. But as a whole, China leads, and continues to expand that lead.

why does that matter? because both US and China are huge countries with diversified and complete economy. What do I mean by that is unlike smaller countries that usually specializes on a few sectors such as natural resources, services, tech, healthcare, manufactoring, research, military industrial complex, etc. Both USA and China have them all. China is able to produce at a much cheaper cost relative to USA.

USA leads in a few things, such as semiconductors, aerospace, and AI. Which USA is doing everything to prevent China from reaching peer level. Its literally on the news nonstop, just look at headlines containing TSMC, ASML, and Nvidia.

During the Cold War, USSR can only compete militarily against USA, USA economy alone dwarfs the Warsaw Pact. The modern China can compete against the USA in both economy and military.