[judk]

I know nothing about Korea, but one possibility is that a small phenomenal success generates an industry or makework that is effectively just siphoning off the value of the core success.

Imagine a startup that generates a $billion in profit from factory made gadgets, but reinvests the profit in bad ideas poorly implemented by office non-workers, effectively middle-class welfare jobs program.

[kyllo]

This.

Koreans have a strong sense of community, and are extremely group-oriented. Sharing, fairness within the group, and conformity to social norms are highly valued.

As a side effect, when a product becomes commercially successful, a large bureaucracy is quickly established underneath it, which subsidizes a lot of other unproductive activity and becomes dead wood over time.