>>149551599
Each Pixar movie had a new technological advancement, The Incredibles being their first film with a primarily human cast, taught them how to properly animate humans, they had to rework the software to animate fat and muscles, looking at pre-Incredibles human designs from Pixar like Al and the guy from Finding Nemo, you can tell their movements look a bit stiff in comparison.

It wouldn’t have been possible to animate Elastigirls jiggle physics two years prior.
https://m.youtube.com/watch?v=3FrbRKPwpoA