China's position as an alternative to western capitalism means their actions almost always goes against the interests of American/Western imperialism. The BRI for example is pretty much going to heavily diminish western imperialism if these countries no longer suffer from sanctions or capital exploitation. Iran not being oppressed by BS American sanctions is a heavy blow to imperialism. The African loans/general infrastructure investments also directly opposes Western imperialism in Africa/the third world by replacing the vulnerability on the IMF and "foreign investors". There is a reason liberals are so pissed about them getting low interest loans. China is bypassing the global financial market and creating bilateral relationships everywhere AND without little or no strings attached.

It doesn't eliminate imperialism of course as long as any country participates in the world economy it will interact with global capitalism on either side, as an imperialist or as a victim.

I also don't think there is any argument to be made about how China does benefit from the existing infrastructure created by western imperialism. China couldn't import resources from other countries otherwise without a capitalist global market that allows it. But as I explained China is mostly acting against the interests of Western imperialism most of the time.