YouTube subtitles usually are not that bad, but they tend to get wrong on key moments.

For example the sentence may be "They decided to rewrite the application in Rust", and the subtitle be "They decided to rewrite the application in rats". They made a single mistake, and it is on the most important word. I guess it can be explained by the fact that these key words tend to be uncommon while the rest of the sentence just flows naturally, that is, you barely need to listen, you can guess most of it.

It worries me a bit because as models get better, they may come up with more and more consistent, but wrong transcriptions. Like a typical LLM hallucination, so confidently wrong that you don't question it.