Since when has it been popular to use Celebrities to do voices for animated movies?

Instead of using voice actors, who have done this for a living, like Billy Wilder? If you look at animated movies, even this decade, and some of Disney movies from last decade, you would see a bunch of Celebrities doing voices for the animated movies. It seems to me, that no matter what, kids aren't going to know who they are. If you look at the cast list for The Tale of Despereaux, you will see exactly what I mean, plus the fact you have Emma Watson and Robbie Coltrane from the Harry Potter movies. Along with Charles Shaughnessy, who played Maxwell Sheffield on TV's The Nanny. Now if you look at the cast list for any of the movies that were made by Walt Disney and his animators, they have professional voice actors, doing the voices in the movie, instead of somebody that was really big and famous in his day, like Elvis Presley, or John Wayne. And what was the first animated movie that did this, with used Celebrities doing voices for animated movies, instead of professional voice actors, that have made this a living doing voices, that now is turning out to being a dying breed.