What exactly do you feet is the foundations of our society other than a representative democracy using a capitalist economic system? We don’t have much else that actually cross all elements of society.
Our society certainly didn't start as a representative democracy or a free market -- slavery was very much still a pillar of the government and economy.
Fast forward a hundred years to the early 1900s and you have things like the Kern Resolution finding peonage and unfree labor in West Virginia mines.
Another century later and today we have ~7 million people under the purview of the prison system in the US [1], including people in prison for debt. (And in many places, these people are used for forced labor.) We have poverty level minimum wages and many systematic failures that prevent people from participating in democracy. It's subtler now than it was a hundred years ago, but there are still plenty of people who are excluded from participating from the economic or democratic institutions in this country.
Also, even if everyone had access, we used to have a vigorous labor movement, and socialism was considered a valuable part of our society. [2] There are plenty of people today who would argue that our society is at least partly socialist (and should be more socialist).
You can't claim a representative democracy and capitalist economy if there are unfree people and forced labor. Or if there are unequal access to either.
