I believe the biggest cause of the national team's discipline issues is MZ culture

Among the current national team members, no one except Son Heung-min has truly experienced life as a proper "private-style" youngest member.
If the '96 line had respected the captain, they wouldn't have caused internal strife with that kind of attitude. Below them, you have Lee Kang-in's insubordination, Seol Young-woo's backtalk controversy, and so on.
It is a total mess.
The generation below them is at a level where they prioritize military exemption over winning medals in public interviews.
It seems this whole situation has arisen because MZ culture has been mixed in under Son Heung-min.
The problem with this '96 line is that if they aren't satisfied, they should just retire, but instead, they keep using media play to ruin the team atmosphere. It is not normal for players over 30 to focus on political maneuvering and media play instead of football.
I believe if Son Heung-min were to step down as captain at a time like this, the atmosphere would become even more chaotic.