Even so, the presence of a capitalist world hegemon is the biggest factor stifling anti-capitalist movements at the moment.
Even if the end of US unipolarity leads eventually to unipolarity for another capitalist power, the transition period in between these two situations will have a higher revolutionary potential and can prevent another capitalist world hegemon from ever emerging.
Even Bloomberg admits that China will grow faster than the combined G7 over the next five years. The question isn't if capitalist hegemony will end, but when.
Your logic (and that of some other people who replied) lingers on the premise that China's "ascension" (for the lack of a better term) equals end of capitalist system. I disagree with that idea
It's just historical materialism. China is building up productive forces that are pushing the limits of capitalist relations of production. Those limits will inevitably be "burst asunder" so long as the planet is still habitable and capital refrains from a nuclear holocaust. As Samir Amin said, it's either socialism or barbarism.