I think 80% could be an underestimate!
https://wave.video/ is the site I use.
Lots of others but I've found it easy - paste in the text, press "go", once it's found the photos etc, click to generate the voice, then once that's done, click "render", download the rendered file and upload to YouTube.
the ChatGPT prompt is:
can you make me a 5 minute video script about [insert topic]
(it's usually about half that time in real life but they seem to give the info in a nice way)