China and Japan have had periods in which they deliberately sealed themselves off from foreign interaction. But I was talking more about being sealed off by geography. So ancient civilizations would have had local interactions, and the more far-ranging interactions often took the form of imperialism (the conquering of territory), as in the case of Alexander the Great, or the Persian or Ottoman conquests.
North Korea is a theocracy with a state cult: the people worship the Kim family, and the priests of that cult hold centralized political power. There's no secular, neutral public space in that country, as far as I know.
What's the relevance of your distinction between religious institutions and folk practice to the article in question? The argument in that article is that secularism/modernity is winning while religions squabble over petty theological disagreements, and that religions ought to syncretize a worthy rival against the likes of neoliberalism, consumerism, and scientism.
Do you mean to say that the folk have always had such a worthy rival in the form of their spiritual practices, so that the squabbles at the official level are irrelevant? Who would be these spiritual folks who don't participate in modernity, apart from the populations of the developing world that would seemingly love to be modernized? If you're talking about a handful of mystics, neo-hippies, and reactionary incels, I don't think they yet constitute a rival movement.