In every other country in the world, there are permanent third parties that draw upon one or the other parties to form governing coalitions. It would be like a family where one husband were permitted two wives, or one wife, two husbands. It is more difficult for such arrangements to work at an optimum, which is one reason our system has produced the most enduring. In countries which remain basically homogenous, there is less diversity to be represented. Japan has essentially a one-party system, with differences being composed through its private cultural mechanisms.
China is also a state that began as a nation several millennia ago.
Its differences are composed through these ancient, learned cultural mechanisms we scarcely can understand. Those Americans who insist China must have a two-party democracy like ours may have to wait a few hundred years, at least, before that happens. Meanwhile, we will continue to celebrate our own unique system, created to fit a unique condition and set of needs. We are the nation of nations, and the Electoral College works as well as it does because it permits temporary special needs to be met. The squeaky wheel gets the grease.