Ahh I watched The Brave Little Toaster as a kid, one of the scariest at the time but still favorite cartoons. Also Once Upon a Forest (1993) was incredible, sadly I haven't seen anything similar lately.
The age recommendations are certainly helpful but they are just guidelines, not rules.
My sister's favorite when she was 5 was Spirited away, she watched it 10 times a day every day for along time :S The movie starts off with the kids parents being turned into pigs for being greedy and the kid works really hard to save them. Not something we planned to show a 5 year old, my brother and I were watching it and she saw it and got hooked. The other sister was so terrified of Beetlejuice cartoons that she had dad burn them xD (those were my brother's favorites). I think the main issue is when kids watch things alone, no matter what. So many parents leave cartoons/movies on just to get rid of kids, instead of taking the time to bond with them.
I remember that toaster movie. Vaguely but it's there somewhere in my mind.
Teaching kids what's real and what's fake early on is important. Maybe society needs to grow up and stop lying. So many traditions include made up characters like Santa. They go from living in a fantasy to a rather shocking real world. That can't be good for the mind.