I put captions on everything. If you type it out ahead of time and put it in, it will time perfectly. If your doing no script, if you speak clearly and have no background noise it will be nearly perfect and you change accordingly.
One thing I do it for is that it makes easier for a fan sub in a different language as they will match the English with the other language. Also I personally feel that seeing CC looks more pro and anyone who doesn't even turn of the auto captions is just showing they aren't combing over everything in their video