Beauty is in the eye of the beholder. Everything is beautiful in its own way.
Remember those sayings, they are the stuff we were brought up on and what we find ourselves saying yet again to the next generation when moments of self doubt raise their less than perfect heads.
Beauty is how you see things, not how they actually are. A perfect pear hanging on a tree is certainly pretty and easy on the eye, but the rotting pear, the less-than-perfect pear holds pattern and texture. It holds interest, and in interest it's own beauty and presence.
Taken a stage further the pear has almost dissolved, fallen in on itself and aged well beyond hope even for a bird feeder. There is nothing remotely 'pretty' about it. It is a hard almost ugly image, but it is nature at work, and yes still a thing of beauty in it's own right.
Pretty isn't always the best picture.