We agree that the Japanese system is far more consistent. I think it's better!
But let's not kid ourselves: if the US instituted a CEFR B2 language requirement [1] for anyone on an H1B visa to gain residency, it would be an absolute shitshow.
[1] This is the new Japanese language requirement.
No, it would not be a shitshow. That's just your assumption.
Do you think I could not pass that test?
For the US to institute a language standard, we'd first have to agree on an official language at the federal level.
Assuming English is the language, CEFR B2 is roughly 75 in TOEFL, such a low standard that community colleges would think twice before admitting such internationals students. In reality H1B tech workers easily blows 100+.