Western European countries got dominant, then got arrogant, letting the USA eat their lunch.
USA got dominant, got arrogant, letting China eat their lunch.
China is indeed getting dominant. They will get arrogant one day. Meanwhile, Western Europe and the USA are still very good places to live.
The pertinent question, then, is who's gonna eat China's lunch?
My guess would be south/southeast Asia (India and Vietnam seem especially promising), but if the US was smart it'd put its efforts fully toward as many infrastructure investments and trade agreements and immigration agreements as possible to create a pan-American economic union. We have the resources and technology to turn every country in North and South America into an industrial and technological powerhouse. We have the resources and technology to finally conquer the Darién Gap and connect North and South America with highways and high-speed rail. We have the resources and technology to go on the offense against drug cartels (while also eliminating the failed border controls and drug prohibitions that keep those cartels in business in the first place).
If we're gonna be imperialists, then by golly let's at least be productive about it.