Why It Took 13 Years to Make the Finding Nemo Sequel

All we know that animation movie takes lots of efforts and time to create.
Some times it took 4-5 years or some times more than that to make one good quality animation movies.
Disney/Pixar's "Finding Dory" which is "Finding Nemo" Sequel is one of them.

Finding dory took 13 years to make complete. Finding Dory released in 2016.
I am not going to tell you all reasons why it took 13 years to make, but one of that reasons i am sharing with you which may find you interesting.

Animation industries main task is making awesome characters and finding its suitable voice, that take lots of time.

This is Hank:

Pixar's most complex character

Do you remember this scene if you watch "Finding Dory" movie,

Walt disiney pictures/pixar took almost 2 years to create one scene for "Finding Dory" (2016).