Limitations Of 2D Animation
I personally love 2D animation, so having to admit its 'faults' per say isn't something I'm overly keen on but here we go.
Its no surprise that 2D animation takes an awfully long time to create. It is much more time consuming than compared with something like 3D animation.
Another down side is the ability to edit, especially when working on paper, for example if there is a change in the scrip and an actor has to re-do the line, the phonetics will change on the character. Causing a either a whole re-do of the scene, or have to do some cleaver editing tricks.
Another disadvantage, is being able to create an almost exact replica of really life. With 3D animation, you can make photo realistic renders, with 2D animation there is the only ability of the creator.