[matt4077]

China doesn’t have a “Supreme leader”. To conflate North Korea and China in such a way is terribly ignorant. Just say “head of state” if you’re in doubt on such matters.

And the issue of title leads to something of an answer: China is (used to be) run more by committee than a single leader with cult-of-personality authority. This is reflected in the official title: General Secretary of the Communist Party (who is also the President, but that role used to be mostly ceremonial). That, plus a healthy dose of racism, is why you’ll find it hard to name any two former Chinese politicians by name (cue “Who?” Joke).

That system probably remained stable in much the same way western democracies remain stable: there were certain rules that, by custom, convenience, or well-engineered competition between centers of power happened to remain mostly respected. Even among undemokratic governments, there are huge differences in how they actually work. China (and also the Sowjet Union after Stalin) have/had something not entirely unlike a resemblance of rule-of-law with regards to the political process within each country’s communist parties.

[mikeash]

I think the question is, how did it end up like that in the first place?

And as far as I can tell, the answer is that the party leadership was sufficiently spooked by the craziness of Mao and the chaos of the Cultural Revolution that they decided to spread out power rather than vesting it entirely in a single person.

[matt4077]

The answer might actually be “communism”. Central to that ideology was a democratic element, where certain groups (workers of one factory, say) would elect delegations to similar groups one level up, in a sort of pyramid. This would repeat all the way to the general committee of the party. “General Secretary” is a title that pretty clearly denotes a certain lack of power: compare the UN, where the top post is named the same, very deliberately indicating their rather beaurocratic leadership function, clearly subordinate to the Presidents and Prime Ministers selecting them.

Now, obviously no communist country ever came close to actual communism. But still: if you spend an inordinate amount of the state’s resources on indoctrination, you will at some point raise a new generation of leaders that cannot completely shake these stories they were told (and forced to repeat) during their rise through the ranks. In such a way, lip service becomes service. These leaders have also risen through the ranks of hundreds such committees with their endless late-night cigar-smoking and scheming. Anyone too daring, or too easily bored, will drop out of the competition long before they get to the actual levers of power. That’s why you get uninspiring beaurocrats, and the colorful cool dictators like Qaddafi or Saddam Hussein only ever get to power in their respective “lesser banana republics”

[seanmcdirmid]

No supreme leader, but a core leader, or, before that, paramount leader.

And I think the term "cult of personality" was invented specifically for Mao as Stalin's spiritual successor.

[graeme]

Well, there's apparently a term within China, "paramount leader", describing their head of state.

https://en.m.wikipedia.org/wiki/Supreme_leader

"Supreme Leader" isn't a term specific to North Korea. It's a loose term denoting the one who has the most power. There's no need to be rude.