The PRC is the biggest economy in the world by PPP and is beating the west in many metrics while the west is falling in those same metrics

Yes

And the PRC is socialist.

Yes but only sort of. The PRC as still ton of social inequalities, a ton of billionaires and many things I would consider basics in a socialist society like free education still are present. If anything they seem to keep getting more and more capitalist as time go on. I agree that the progress of China over the last few decades is still a huge win for socialism but I don’t see the death of capitalism you seem to be suggesting any time soon