[lifthrasiir]

As someone who did work on subtitles in modestly popular videos as well, I believe there should be two subtitles---one for disabled peoples and one for language learners. They serve overlapping but not entirely identical purposes. The point 1 is well said though I think Tom Scott aimed his subtitles mostly to the former, as like television regulations.

The points 2 and 3 are comparably of less concern in my opinion. I don't watch TV nowadays, but when I did I used to watch programmes with on-screen captions (as opposed to optional subtitles, pretty common in East Asian channels), which never faithfully reproduced what has been said, and I was fine. Maybe I was more annoyed if I were able to turn captions off and only occasionally turn them on, but the whole points don't really match my experience.

The point 4 is what I'm most unsure about. I believe this kind of experience can be replicated by who can hear some but not all of foreign words and need subtitles (of the second kind) to connect them. For example, I can hear and speak Japanese but very slowly, so I normally have Japanese subtitles turned on. And I think I often experienced a lack of understanding due to my weak knowledge of Japanese, but never experienced such a conflict in understanding. Maybe the sensory processing issue has a substantially different mechanism to my model then?

> I'm curious to know if you can give an example of that?

Filler words, cut-off words, etc. Faithful transcriptions need to reproduce them (and yes, I also did some transcription works and that was really annoying) but subtitles needn't and shouldn't in most cases.