Netflix is improving in some locales, but remains a shitshow elsewhere (experimentally: countries with under 40M population). E.g. there are German and Polish subtitles for everything; there are almost none for Czech. They do things like providing them for only season 1, but not the rest, or don’t bother even with their own high-profile shows. Slovak viewers can choose between Slovak, Polish and Ukrainian subs, but not Czech - even though the entire country fluently understands Czech, an extremely closely related language. Netflix doesn’t care. Or have even nominally-useful support.

If the Netflix app allowed side loading my own subtitles, it’d be fine. But of course it doesn’t and won’t.

So guess what I do when I finish Narcos season 1 and discover lack of subtitles in season 2. Or when a show available on Netflix doesn’t have any (and I want to watch it with my spouse who can’t read English subs quickly enough).