I made the comparison because at the beginning of the video, he talks about how they split into two teams; one used jQuery and the other React. Apparently the jQuery team moved significantly slower. I found that hard to believe given all the hacks they had to with React later on.
The React team was probably quicker at responding to the designers' ideas. The stuff that took a longer time was getting all the transition animations to work, which can be difficult in any higher-level framework.
