The theory that non-capitalist societies can have thriving long-lasting economies that produce new innovations and lift their people up is pretty questionable so far.

I can't think of a single example where there's not at least a core nugget of capitalist incentives driving things.

Sure, let's layer on some socialist policies, I'm all in favor of turning that dial quite a bit further, but that's turning a dial, not blowing up the whole machine because it's not working quite as well as we'd like it to.