I like how there are multiple people in this thread who conflate worthwhile technical skill with creative leadership.
In truth being good at your job should be a requirement especially for animation and artistry and in that regard the study of animation is essential for continued mastery.
But to be the one in charge you got to have worthwhile ideas and drawing from a wide pool of varied experiences is essential in that regard.
Not having those experiences to draw upon isn't a bad thing for an animator, but again it is for someone who is a All-in-One Border/Scriptwriter or Showrunner.
We have beautiful examples of artistry from the medieval and renaissance era but the majority of which were commissions of nobility portraits, mythology, religion, or history not of original works. That doesn't make them bad but more often than not they were just following someone else's idea and often using actual people as models, which requires an outside presence that someone had to have and that caries through to this day.

And the reason the Pixar stuff is shit is because instead of looking outside of animation to other sources the creators only looked at themselves, and a self portrait can be good via a skilled artist but rarely are they the masterpieces.