I think your oversimplifying here. I think economic growth is strongly tied to stability but it's also strongly tied to mechanisms. Pricing as a vehicle for measuring supply and demand simply outstrips everything else we've tried. Even this article mentions how difficult it is to centrally plan supply and demand and how large the bureaucracy needs to be. Perhaps some technocratic socialism could create a computerized bureaucracy large enough to solve this problem somewhat well, but I still think computer models are going to be inferior to actual markets. While markets do have plenty of imperfections they are kind of like democracy, the worst system for supply and demand except for all the other ones. As for why having good systems of supply and demand affects innovation dramatically the short answer is that it forces innovation to conform to an approximation of useful (creating demand) rather than just novel (which is what happens in a lot of purely academic projects). Non-capitalist systems have also done poorly at creating competition and competition seems to be a central force in generating quality (in fact the biggest failure mode of capitalism seems to be anti-competitive monopolies).