Even before that: in the 1950s when animation moved from theaters to the small screens of television, animators were advised to simplify everything and cut out details because audiences simply could not see them. Also, a lot of shows were produced on the cheap by small studios with a handful of artists who weren't necessarily that good. So Western animation on TV started out bad and stayed that way until the outsourced Japanese animation came back in the 1980s.

Even before that: in the 1950s when animation moved from theaters to the small screens of television, animators were advised to simply everything and cut out details because audiences simply could not see them. Also, a lot of shows were produced on the cheap by small studios with a handful of artists who weren't necessarily that good. So Western animation on TV started out bad and stayed that way until the outsourced Japanese animation came back in the 1980s.