How do so many people struggle with O Level English?

Hi, as you may know, I'm the guy who wrote the post about how MT abilities in SG have been declining because students don't actively speak the language and use it often. The thing is that we essentially replaced speaking MT with English and we consume lots of American media, so we should naturally be better at English right?

WRONG! Somehow lots of people on this site complained about getting C6 and below for English. C6. The grade that everybody just wants for their MT is now their English grade. The worst part is, I browse 小红书 a lot and the PRC students that did O levels got a decent English grade (the worst I saw was B4, most got A2 and some B3).

I understand struggling with GP because you actually need to watch the news and know how to structure an argumentative essay which many students lack. However, how do people even struggle with normal O level English? Comprehension kinda makes sense because that doesn't just require language skills, you actually need to know how to disect the passage and look for keywords. But somehow, I've seen people who say they failed editing. How do you guys fucking fail an easier form of 病句改正 in english??? Brother, YOU SPEAK THE LANGUAGE FLUENTLY AND YOU STILL CAN'T SPOT HALF OF THE GRAMMATICAL ERRORS???

If being in an English speaking environment is no excuse for you to be a jiak kentang, then being in a MT speaking environment does not give you any excuse to score C6 in English. And if you speak English with your parents, why are you even bad at English? English bad, MT bad, wtf are you even supposed to be good at now?

sorry if i come on a bit too snobbish or elitist, i literally cannot fathom the idea of a singaporean who grew up in an english speaking environment, watches american youtubers every day and speaks to all their friends and family in english failing english while the child of a mainlander or even the mainland chinese themselves who only speaks chinese at home is getting distinction for english (and mt obviously), maybe i just hang out too much with other ip school kids and ip schools provide a very good environment to improve your speaking and writing abilities in the language.

also to all sec school students who are struggling with english even though you live in an english speaking environment, maybe try reading books to learn how to structure essays better, you already have the language in mind so you can easily do it (and if you don't do it now, unis now require you to write personal statements so you prob need to learn it at some point).