Cannot Extract Subtitles from .VOB files

[ToiletDuck]

Unlike DVDs, (UHD- and HD) Blu-rays only support image based subtitles.

Exactly that ↑ .. 

Only have found/extracted image based CC's from BD's AND DVD sources   
Never encountered txt,srt.. based subs... in any form, size or scent in my huge dvd/bd library ..

But haven't checked near half of it either..so..
.. hard to phantom that .. !