YouTube has transcripts now. On desktop, in the ellipsis menu under the video title on the right. On mobile, a "show transcript" button after expanding the vide

YouTube has transcripts now. On desktop, in the ellipsis menu under the video title on the right. On mobile, a "show transcript" button after expanding the video description. They're not exactly formatted for nice reading, but on desktop it's possible to copy and paste the whole transcript wherever you like. I find the speech recognition astonishingly accurate. Of course you will still find mistakes, but overall it is almost always possible to get most of a video's content much faster just by reading the transcript.