Universal suffrage was already being demanded prior to WWI, and was itself a gradual process. For example, Asquith was prepared to put forward a bill to enfranchise some British women, as happened in 1918, in 1914. The war, however, delayed this, and French women didn't gain the right to vote until WWII. As for things like an 8 hour day, pensions, etc. these were already appearing even before WWI, as can be seen by the reforms enacted by Otto von Bismarck, and the People's Budget in Britain in 1912-13. While WWI may have helped accelerate these developments, steps were being made towards them well before WWI, and probably would have taken place without it. Plus the growth of/growth of support for corporatism and state-intervention in the economy after WWI would indicate that "those at the top" had, if anything, grown stronger.