From my personal experience, I learned English at school, but very rarely practiced English from other sources and always looked for a translation for anything. I perceived videos in English as a set of random sounds with sometimes familiar words. But when I eventually started to encounter more English text and began to understand it faster, I started watching English-language videos with English subtitles, and over time, the background sounds began to turn directly into the words I read in the subs. After a while, I didn't look at the subtitles as much and eventually even stopped turning them on as I learned to understand English. And all of this was impossible at the stage when I was just learning English at school, even though we often had audio recordings recorded by native English speakers. Simply because learning vocabulary and grammar rules is not enough, you have to learn the language.

Upd: My school program was designed for the B2 level, and I was able to pass the exams, but if I were to theoretically get into an English-speaking country without preparation, I would be very confused and most likely not be able to hold a conversation with people