i think a lot of the time it's just a lack of effort or quality control on the streaming services part. streaming subs have gotten so bad it's one of the main reasons i prefer to just watch torrented stuff now. watching the simpsons on disney plus they will literally miss whole lines of dialogue a handful of times per episode. watching trek TOS on Netflix the subs are constantly slightly out of sync with the audio by halfway through an episode. it's maddening