What makes it difficult to make an animated movie rather than a normal movie ?

I'll try to provide a layperson reply as a layperson who really has only a little technical background in animation. Animated movies originally require thousands or tens of thousands of handpainted individual cells in ordr to create the illusion of movement. Such technical and artistic skills required one, two, or even three years to complete one movie. Additionally there was or continues to be stop-action animation (not the actual term for it), but there was like with WALLACE AND GROMIT movies using claymation which requires that each movement be shot one at a time. Today many animated films have adopted digital technology that required sophisticated computer programming to mimic realistic movements and appearances of background shots as well as characters, among the most difficult has been replicated human hair appearances. Different individual computer programs are required for individual different movements observed on screen, one character can be composed of up to 300, even 500 different programs. Even digital movies can take three, four, five years to complete! And even now digital pictures today still need to be transferred to 35 mm film where they are then presented in theaters. Live action and also live actors are usually required to independently create an in sync voice and computer digital match as well as sometimes having to perform live action in which sensors are then used to transfer live action into a computer generated animated character. In sum, animation today with the introduction of standard 3-D technology represents a major advancement in its ability to rival live action movies and may one day even threaten the use of live actors (though the same was said of computers winning chess tournaments).