This makes sense because there's less of a need to travel abroad for studies, and it has also become much more difficult for Chinese nationals to study abroad over the past 4 years (eg. Zero COVID from 2020-2023, Visa restrictions in the US).
Edit: The TOEFL's methodology has also changed to actually test for speaking and writing fluency. Before, the TOEFL would overindex reading skills, but not speaking and writing.
When fewer people take a test, I would expect the average score to go up, since the people who do take it are likely more motivated.
But it's all within the range of historical variation anyway.
And this is even a good point as well - the EF SET isn't really used in most cases where English fluency is critical (eg. College admissions in the West, Citizenship/PR applications in much of the Commonwealth, etc), so the kinds of students taking EF specific tests might be less prepared or knowledgeable about English and Western culture compared to those preparing for TOEFL or IELTS.
before video games and other popular culture things would help people learn / keep practicing a language but now china has a vibrant video games market e.g black myth wukong.
saw it happen in taiwan.
That doesn't make much sense, unless millions of people forgot a language in 4 years.