I think there are four reasons.

1. Extra points

2, language advantage, accounting for about 10-20 points.

3. The liberal arts papers are approved by Koreans themselves. I heard that the answers that are not too outrageous are basically not deducted (you can check that the high scores are all liberal arts, and Korean students are really not very good at science).

4. However, it is undeniable that Korean people attach importance to education, at least among ethnic minorities, not the first but also the top three. (For example, among the first batch of 10 members of Mathematics Hope Alliance, Yanbian No.1 Middle School is the only national middle school, not to say that No.1 Middle School won the Olympic Games nb, but if ethnic minorities want to make achievements in this respect, they must be Korean. )