They also projected the GDP in purchasing power parity and military spending and workforce levels. Those are all measures which favor emerging large population economies like China and India.
Thus they project that China will surpass the US in terms of Asia region power and that India will nearly match the US in terms of Asia region power by 2030.
The view of comparing military power is also a distortion. US equipment is still superior to Chinese equipment. The US has more planes and the equipment is better. US bombers are vastly superior in terms of range and bombloads.
The US has 11 defined aircraft carriers but the US also has 10 mini-carriers which are called amphibious assault ships. Those mini-carriers are about 40,000 tons and can carry about 40 planes. One of the US mini-carriers can match China’s refurbished Ukrainian “aircraft carrier” in terms of size and number of planes. China new domestically built aircraft carrier is also small. On paper, China could have two carriers but combined they are less than one of the US super-carriers which can deploy 80-100 planes. China’s fourth or fifth aircraft carrier will start getting to the size and number of planes as one of the US carriers.
After the various caveats and details, it is clear that China and India are emerging and will be far more powerful in Asia. Japan, South Korea and ASEAN (Indonesia in particular) will continue to have substantial and growing power. It is a question of timing and maintaining high levels of economic growth and development.