To add to that, China's simplification process happened during the 50s and 60s, back when China was deeply impoverished, had massive famines thanks to the Great Leap Forward[0], and had basically zero international influence (didn't even have a UN seat). They weren't in a position to influence Japan in any way. Not to mention that Japan was in the opposite camp during the Cold War.

[0]https://en.wikipedia.org/wiki/Great_Leap_Forward

I mean what you're saying is correct, but I never said China instantly switched everyone over to simplified once China decided in the 50s/60s.

I am saying the superpower it has since become has "forced" most other countries to defer to using simplified rather than traditional.

After looking this up, yeah you are right. I just assumed there was a conversion of Traditional->Simplified for the most part because I had noticed earlier in my life that most of the written forms of kanji (I saw) were written in traditional form and only towards the past decade or so have I noticed that there were more characters that looked "simplified"