Don't understand estimate the US. It is badly governed, as are we.
But it still has a dynamic economy, enormous natural resources, a significant lead in front edge chip tech, which is iron clad protected and will shape the next thirty years or so, a relatively educated workforce and holds the world's reserve currency.
China has made huge leaps, but well over half of its people still live in poverty. That's real poverty too, subsistence living in many cases. It also has a massive problem with fresh water, and an incurable demographic decline. Growth is slowing in China and a vast property bubble will burst one day. The overwhelming Communist suppression of any kind of dissent and disregard for individual choice hardly helps
Shangri La it is not!