You'd be surprised how many people use movies to improve their English language skills in the countries where English is not spoken natively. Just visit a college dorm of a developing country where English is not spoken natively. When I was in college, Internet access was very limited and we used to watch Harry Potter movies in loop, pausing at every dialogue and check the meaning for words we didn't know.

Of course I'm not telling watching movies would give anyone university level English proficiency, But watching movies to improve language skills is real - https://explore-blog.griffith.edu.au/improve-your-english-watch-movies/ .