Your estimate is way too optimistic. But also what it doesn't get is usually key subject content and what it does get is low hanging fruit guessable from contex

Your estimate is way too optimistic. But also what it doesn't get is usually key subject content and what it does get is low hanging fruit guessable from context. Sometimes I try subtitles on something I cannot understand (because English is my second language) and that has not helped ever, it's always gibberish. I tried going subtitles only a few times and gave up because I have to rewind and turn on sound every few seconds.