While the tests of English language proficiency are possibly deficient, I would say the first problem with learning English (or any other language), is the way the formal language courses are designed.
xxx
A retired "average skills" pilot, my skills with languages are outstanding, as I speak fully fluently (native level) 3 languages, speak 2 more quite well, and a last one soso - enough to get out of troubles, ask my way around or order meals in a restaurant. And I can understand others, say hello/thank you, but not speak...
xxx
The problem with learning languages are the language schools and school programs. Teachers who are not natives of that language, can barely pronounce and use poor grammar, and uncommon vocabulary. Any person, native of a language, call it English,
even not certified teacher would be a better teacher, than a graduate teacher who has a degree in English education, but never practiced English in his life. A school, say in Budapest, would be better hiring a British born secretary (not even teacher) as teacher, than a school teacher who teaches English, but can barely speak it.
xxx
I now assist the Alliance Française in Buenos Aires, and an American language school in Buenos Aires as well, as volunteer teaching French and English to teenagers and young adults. Yet, I am not a qualified teacher. But, I convinced the school management of my teaching ability as I hold a (pilot) "instructor" licence, which made them believe or understand that yes, I can instruct = teach... in classrooms.
xxx
Ask yourself how kids learn their language (from their parents) when they are of low age... Do you see mother and dad taking their boy or girl on their lap, and tell them "today we will learn this vocabulary" and the rules of grammar, conjugation of past or future tenses, and reciting lists of past participles... It is obvious that kids learn with simple conversations, coloring books, "do you want a candy", songs on the radio, comic books from Disney, etc...
xxx
Do you want to know my "classroom equipment" for English...?
CNN News, from TV, 15 minutes in Spanish then same in English - MASH 4077 as TV shows - Beatles CD music records, or Celine Dion (they learn some songs) - Monopoly game (Atlantic City, NJ streets) - USA Vogue fashion magazines for girls, USA Car & Driver magazines for boys - and any group conversation of common interest in the classroom - A drink in an Irish Pub, after school, beers, if over 18, fruit juices if minors - and only English is used. I never say a word of Spanish. And yes, they learn the practical words, even the bad ones not to use. Grammar, basically none. Vocabulary, no isolated words, but small sentences. Spelling, we dont practice much, but correct pronounciation is important.
xxx
You can replace 4 years of "formal English" language classes in a college, with 3 months on location in the country. How did I learn English as a teen...? My teachers were Frank Sinatra, Dean Martin, or Paul Anka, and text book was Flight Magazine. Bill Shakespeare... never heard of him. But I enjoyed theater plays of G.B. Shaw...
xxx
Happy contrails