The legendary 4-2-3-1 saw France squeeze every bit of value out of Zidane and Henry.

‌A formation that doesn't lose, but is also difficult to win with.
Even with Zidane and Henry, they took a lot of heat for not scoring enough points, but they also conceded very few goals.
From the opponent's perspective: France has 2 defensive midfielders and 5 midfielders, so it's hard to win the midfield battle from the start + it's Henry, so pushing the defense up feels risky + if the gap between defense and midfield opens up, Zidane goes wild = let's just sit back and fight too = super boring "swamp football" (defensive/stagnant play).
Korea also played proper "swamp football" with a 4-2-3-1 during the Bearback era and took a lot of criticism for it.
Whether playing against strong teams or weak teams, it was always swamp football.
At the very least, once a 4-2-3-1 is set up, avoiding a loss is possible.
For Korea, we just need to deploy Son Heung-min as the lone striker and Lee Kang-in as the attacking midfielder.
There are so many variations of the 4-2-3-1, but since the 4-2-3-1 is fundamentally built for counter-attacks, Son Heung-min doesn't even need to come back to defend.
Since Lee Kang-in is the attacking midfielder, his defensive burden can be low.
However, we already threw in the towel during the Bearback era because of the frustrating swamp football; will we be able to endure it this time...?
Even with Zidane and Henry, it was proven that the ceiling of the 4-2-3-1 is low, but its floor is definitely high.
At one time, the 4-2-3-1 was the favorite formation of many managers.
A formation that doesn't lose? It's a sweet deal.
Anyway, it earns you points, and the lower the squad quality, the more you can rely on the "prayer meta" using 5 midfielders + counter-attacks.
Of course, if things go well, there's the dream scenario of alternating between the 4-2-3-1 and the 4-3-3.