The architecture of “not bad”: Decoding the Chinese source code of the void

Maybe there's a difference in frequency of usage, but we also say things like "he's not wrong" pretty often in English.

I reckon a decept part of that is due to American English vs. British English.

A great example of this is the Korean War, where a British brigadier in an extremely difficult situation told an American general "Things are a bit sticky, sir" - who interpreted it as "Could be better, but we're holding the line". The misunderstanding resulted in 500 dead and captured.

FWIW I’m not quite convinced there’s that much of a dialectical divide: “Not bad,” “he’s not wrong,” etc. sound entirely natural to me in American English.