Is that really so problematic, though? It's the same as ABC iView and SBS OnDemand, from what I can tell... Perhaps this is just to comply with local law, then?
Netflix can provide both English subtitles and closed captions (as seen in some Korean shows). They simply choose not to offer them for most English-language titles.
I honestly thing that they’re created by third parties who just run the audio through an AI and call it a day.