Another point is that it is not democracy that brings the enormous increase in production, or "prosperity" of capitalism. It is the undemocratic institution of wage-labor or wage-slavery that is the basis for increased production. The more democratic the economic institutions,as in moving to socialism, the less production. Production will be optimized based on wants and needs derived from mass democratic decisions , not the drive to maximize profits for the few.
As evidenced by the slower pace of work in the Soviet Union, as compared with capitalist countries, to the extent that the workers have more power in society, i.e. the more real democracy, they are likely to slow down production. The working class doesn't crack the whip as boss as much as the bourgeoisie.
Part of the reason China has to have capitalism now is that they are in a life and death competition with imperialism ,and socialist relations of production wouldn't be able to keep up with the pace of production in the imperialist countries. Socialism is superior at distribution to capitalism. Capitalism is superior to socialism in size of production.
Affluence or prosperity is a fit between wants/needs and production. Wants and needs do not inherently constantly grow at the _pace_ they have under capitalism. Slow down and enjoy life, people. -
Come the revolution , more leisure, less working hard.
Anyway, capitalist production is not democratic, so it is not liberal democracy that has created capitalist "prosperity".
Charles