Why is there a concept of physical attractiveness?

I have been pondering this since I was a young teenager. Even as young children we recognize who is beautiful and unattractive, even without influence from adults. Why did God build this innate nature in us.

I totally understand the fact that there are people in the Bible that have traditionally unattractive features. Stutters, shortness in height, etc.

Why does God allow us to think this way? Before you answer I’ve already heard “wouldn’t it be boring if we all looked the same” and similar to such things.

I understand that the Bible demonstrates that outward beauty is vain and fleeting and that fear for The Lord should be an attractive trait. However, that is never the first thing we see of a person. I mean wouldn’t it be better if in away we were basically all on the same level of attractiveness? Instead, some serve as basically the stepping stone to show the attractiveness of others.

Also I know the Bible describes Jesus as an unimpressive man.

TL;DR:

Why did God make some of us ugly, and others beautiful?