I definitely agree that Chinese imperialism sucks. There are a handful of genuine criticisms towards China that even people who admire China must admit are very bad policies. The treatment of the Uyghur Muslims is particularly heinous, although I don't know if it's considered imperialism. It's just that the shit the US gets up is orders of magnitude worse.

Imperialism isn't a policy that states have, that's an idealist distortion. Imperialism is a global system of extraction from the imperial periphery into the imperial core.

As of now, in our current stage of capitalism the global economy looks like this:

Periphery countries: These countries have their economies focused around a few major commodity exports. They might extract resources from the ground in the form of mining or agriculture, they have limited industrialization or only specialized industry they cannot branch out of. These are places like almost all of Africa, some of Asia, India straddles the line between this and semi-periphery, and some of Central and South America.

Semi-periphery countries: This group has grown in size over the last decades because of off-shoring industry from the imperial core into places with more exploitable labor, these are countries like Brazil, Mexico, China, and Russia (those last two are a bit different), they have industry, but they are still export focused.

Core countries: These are the group whose economies are focused on consumption. They exist at the end of most global supply chains, they import finished cheap consumer commodities or close to finished commodities, and export little. These countries hold most of the capital on Earth and their bourgeoisie controls global finance, they have a monopoly on loans for poorer countries that need them for development and they exploit that by extracting high interest rates on debt. Another major export of the imperial core are tools of rent extraction, IPs: licenses on the use of essential technologies, proprietary software, etc. The actual commodities exported by the imperial core are usually explicitly monopolized (only capable of being produced there) or indirectly monopolized by using their financial power to overprice their exports. Finally, they direct surplus production into a massive military industrial complex, and they use this military as the final way to enforce imperialism using extreme violence against the inevitable resistance to this system.

The core used to directly control periphery countries, but after that got too expensive, they divided their colonies up into tiny states that couldn't hold themselves up economically on their own, so they required investments from imperialist finance capital to survive. This is neocolonialism, where the colonized country is free on paper, but their economy is controlled by finance capital from imperialist countries. Their exports are underpriced while they pay overprice for the commodities they require and pay steep interest rates on debt.

It is in the interests of the these periphery countries to find ways to weaken the monopoly power of the imperialists as it is their primary weapon that is keeping them underdeveloped and unindustrialized. We should support them in doing so.

The semi-periphery doesn't have conditions as horrible as the periphery, but they are absolutely still exploited by imperialists in a similar way to the periphery. Semi-periphery countries also can have semi-imperialist interests: they do not actively maintain imperialism, but they have something to gain from looking the other way when they import cheap commodities from the periphery, they may even invest abroad and start their own micro-empire. Historically it has been where most socialist revolutions emerge. The semi-periphery is prone to revolt because of its independence, it's existing base of industrialization makes it easier for them to achieve self-sufficiency from the core.

Russia, China and Iran are all good examples of semi-periphery countries that have become a serious nuisance for Western finance capital. Russia is undermining the precious oil monopoly they built their empire on, China is doing all sorts of things counter to their interests, and Iran is going to war against them.

I do not think it is at all useful to advocate for the destruction and balkanization of Russia or China, despite their flaws. That would just entrench Western imperialism for God knows how long, and just put all the people living there under a much, much worse neoliberal regime (you know there's no way a free Tibet and Xinjiang wouldn't just become Western proxy states, I cannot see that happening any other way in the real world). The semi-periphery isn't the real enemy of the global South, the real enemy are the bourgeoisie of the US and Western Europe (with Canada, Australia, and New Zealand as honorable mentions).

And, no, this does not imply I advocate "swapping" the imperialist power. China notably has been doing very well at undermining US and European monopoly power in Africa and in Asia. Competition decreases the power of unequal exchange and interest extraction which are based on monopolies, and that is not at all useless for the people living in Africa and Asia, it means they can build infrastructure without paying through their teeth in interest.