In Chinese, affirmation is often compiled through negation:

没错 (méi cuò) = “not wrong” = Right

不差 (bù chà) = “not bad” = Decent

还行 (hái xíng) = “still passable” = Okay

没事 (méi shì) = “no problem” = It’s fine

In English, this feels bizarre. If something is good, you say:

Nice

Great

Perfect

Brilliant

You name the quality directly. You point at it. You own it.

In American positivity-laden, self-marketing, businessy English perhaps. But in the UK “not bad”, “could be worse”, “not wrong”, “can’t complain”, “I’ve had worse” and so on is often as positive as it gets, or at least was for a long time. American positive-speak gets on British people’s nerves; it’s perceived as boorish, boastful and unsubtle. And “no problem” is common in English all over. British people do say “brilliant” but only when they’re being unusually enthusiastic, or fake, or sarcastic.

I feel like the author is exaggerating how the languages work, people say 对 and 好啊 in Chinese and “not wrong” and “not bad” in English pretty frequently.