Probably helps their vocabulary and social skills. With everything there's always cons tho. I would imagine that cartoons also create unrealistic expectations. A child (for many years) watches characters go on adventures (often with superpowers or always coming out unscathed). And the characters don't have to work at taco bell or go through an abortion. I imagine kids go through a ton of cognitive dissonance once they hit adulthood (because of cartoons).
It makes sense. The earth is full of holes, and we're essentially living on plates that move. The idea that humans can go to 7.6 billion people (and completely obliterate the ground underneath) and call it "progress" is kind of fascinating.