helps directors get what they vision to see into the movie instead of trying to do it unsafely and real
it gives actors more freedom to choose how they look in the movies as seen above her arm was the only FX used in Mad Max Fury Road that's how it changed the movie and her appearance
cons
Special Effects have become a crutch for film-making
Takes away from the original art of making the film
The better the effect, the less credit there is for it