>>713428475Basically japanese martial arts have a gap in the meiji period where they weren't practiced due to government policies resulting in most of them dying outright due to lack of successors, and the rest getting watered down to almost just the ceremonial bits. Nowadays the most serious schools aren't that different from HEMA in regards to approach and historical accuracy.
For chinese ones it was more complex, but essentially still just politics discouraging or outright banning them, leaving only non-violent larping. Just as a combination of many political forces over a long period rather than just very specifically the central government going out of its way to undermine the practice.
SEA is a whole other case, what with MT and flip shit being actually still decent, but I'm not knowledgeable enough to even tldr it for them.
Oh, and if you were wondering why the jap government hated that shit it's because it came to power explicitely thanks to those very same practices, and it wanted to avoid losing power in a repeat civil conflict.