High School Credit System and the 5-Grade System Make Advance Learning Unavoidable

‌To be honest, if you were only focusing on the CSAT (Suneung) without the burden of GPA/school records,
it would be better to focus on the current curriculum and peak your skills in time for the CSAT rather than doing advance learning.
However, under the current admissions system, if you don't do advance learning, you will fail the rolling admissions (Susi) process.
I didn't fully understand this at first,
but after my child entered middle school and I heard explanations from admissions consultants and stories from parents of seniors who successfully sent their kids to top universities,
I realized why advance learning is so desperate.
Once you enter high school, the battle for rolling admissions begins from the first year.
As soon as you step in, before you can even process it, the midterm exams are already upon you.
And there is an immense amount of work to do. Besides Korean, English, and Math, you have to prepare for other subjects,
and you have to handle various performance assessments as well.
At the very least, for Korean, English, and Math, if you haven't completed some level of advance learning before entering high school,
even if you work hard and follow the teachers honestly,
even if you do well in Korean, English, and Math, you will have gaps in other areas.
Children who have done advance learning can reduce the time spent on Korean, English, and Math and allocate more time to other subjects and performance assessments.
Otherwise, you simply cannot compete.
If you are aiming for top-tier universities under the 5-grade system, you must eliminate or minimize the number of 2nd-grade marks.
Thinking back to my school days, there were always students whose overall grades weren't great, but they were exceptionally good in other subjects like Science or Social Studies.
If you only focus on Korean, English, and Math and neglect those subjects, you will end up with a 2nd-grade mark.
Ultimately, to survive in the current rolling admissions system, the 5-grade system, and the High School Credit System,
at the very least, some say you have no choice but to complete the curriculum for Korean, English, and Math—or even Science—before even standing at the starting line.
Saying "Advance learning isn't that important, doing well in the moment is more important"... that is truly just an "old school" story (Latte story).