This is pretty far from the standard narrative, but I think something happened 300 years ago. A different group moved in, and destroyed the more beautiful creations of the older group. Where there were statues on churches, these were replaced with gargoyles.
I think the nose destruction you raise is a part of that - its a simple way to 'uglify' a thing of beauty. Those Egyptian statues are representation of people that were in perfect proportions and display idealised geometry.
https://www.emotions.64g.ru/prof3/pro04en.htm
So, I think they were beautiful and destroyed intentionally by whoever conquered or moved in over the preceding group.