I was having dinner with a professor recently and he professed his amazement at how the American system seems to work so well (having been born in a communist country). This applies to other countries also, but we use the American example.
It basically gets down to “checks and balances”. Don’t give any one group too much power. Concentrated power is the problem with communism and related “collectivist” societies.
People are good at forming teams. That’s our social nature. The American system works because no one team is allowed to have too much power. We form multiple teams, all with their own interests and goals. (Think “government team” and “industry team” and “health care team” and “legal team”, etc.)
Once you belong to one of these teams, you adopt the goals and perspectives of your team. We are social creatures. This comes naturally to us.
If no single team has too much power, the teams keep each other in check. The people on each team all see things similarly from their own perspective. That perspective differs among the teams. The teams work together but also keep each other in check.
The key here is that we have a system that prevents any one team from gaining too much power. It’s a constant dialog, a constant “back and forth” as each team grows and shrinks in power relative to the other teams. The end result is overall stability.
The democratic legal process is the means by which we prevent any one team from getting too powerful. Once we prevent concentration of power, the natural dialectic of the teams keeps everything going.