Every fairy tale with a good king/queen/princess/prince?

Or One Thousand and One Nights has the king killing his wifes left and right, but by the end it’s alright, because he really loves his current wife now…

Since you are asking for cautionary tales, The Fisherman and his Wife might a better fit. Just be glad of what you have and don’t strive for advancing.

Rudolph the rednosed reindeer

It is bad to be different as long as it is not economically exploitable