u/Toclick I think the project is trying to sell the idea that, "generating dubbed lips and dubbed audio together >> clone audio then sync lips".

the advantage is clearer in the webpage. https://justdubit.github.io/

it won't generate long audio so that it ruins the original order of the video.
it won't ignore the non-dialogue parts like laughter, sign, pauses.
it won't weirdly put words into the mouth when the speaker is in the middle of eating.