South Korea is notoriously known for Video game sanctions in entire markets. and considers Video game as a entirely as a explicit harm for teenagers/childrens. Reference1
The law that passed on 2011 is called "Teenager Protection Act" and its successor, "Game Play-time selection act" (a.k.a. both in general called: "Shutdown Act") presented by Ministry of Gender Equality and Family, requiring all video game service provider to implement a South Korean National ID Verification System in order to play a video game, and shutdown the video game service entirely for him/her/its game session from specified time if he/she/it is less than 15 (or 19 depends on his/her/its parent's configuration) years old.
If you think this is a human rights violation, South Korean government thinks that's a no. See 2011한마659 Case
But this was a hassle for Console market, (shutting down when it is 10PM-8AM or shutting down for specified time) Therefore Microsoft Korea implemented its all of its service as 18+.
Requiring South Korean National ID Verification with age over 18 if you want to play any Xbox Live game.
Since the Minecraft's migration to Microsoft Account REQUIRES Xbox Profile, which CAN NOT be created without Xbox Account, anyone under 18+ right at the moment has migrated to Microsoft Account can not use the Minecraft Launcher and Log in to his Minecraft account.
Currently, South Korean Minecraft players (especially, Java Edition Players. which previously did not require Xbox Live account) is outraging as this is equivalent of Deleting son's minecraft world but in larger scale.
You are directly affected by this. If you are under age of 18.
Even if you are not, this could lead to a major decline in Java Edition's ecosystem in South Korea, since majority of Minecraft players are in younger audiences.
It will be rather helpful (even if you are over the age of 18) for entire Java Edition ecosystem, If you help us to move on and fight the current situation we are facing.
This is just putting the problem away for a moment, This can affect all games.
Please refer to I don't play Minecraft: Java Edition to get full insight.
This incident still means your favorite games on Steam (especially, indie-games which uses network connections) might not support South Korea entirely.
Since South Korean government (especially, Ministry of Gender Equality) is strict about applying Shutdown act to every single game and considers none about the indie-developers at all.
But this is literally impossible for Indie-game developers to implement since it costs lots of money!
(Declaring a Business in South Korea, Integrate an Government ID Verification API and Finally applying shutdown act on global server especially for users residing in South Korea (just for South Korean citizens because no other country in the world requires game-developer to implement this))
This could affect every single indie-games that uses network connectivity at all.
1: Yes, I know it is CNN (left wing of media), but hear me out. but that news is not lying.