Seems like every youtube videos doesn't have "appropriate captions"

Hello,
I can’t seem to find any youtube videos that have “appropriate captions” and thus cannot import most youtube videos.
Do they have to be videos with transcripts created by the youtuber channel themselves?
Am I better off just transferring the videos to mp3?

Not all youtube videos are without subtitles. It depends mostly on which YT channel you look at, if the author has added subtitles or not.

The only way I’m aware of, to get the text, is to convert the YT video to mp3, and then import it. Better then nothing.