They’re a secondary sexual characteristic, so it seems like something that would get attention.
“Small” breasts typically are still large compared to a man’s chest.
There are other factors than size anyways, for any feature. For breasts as an example, symmetry, skin clarity, and firmness will also signal a healthy prospective mate.
“Small” breasts usually actually means “not sagging due to age”, as naturally speaking breasts, cheeks, and the neck of humans are common areas where sagging due to collagen levels can be witnessed in older age, so these are common cited areas of sexyal attraction.
So “small” breasts really just means “not old”, which is fairly normal to signal the health of a potentional sexual partner.
Ok smart guy, explain this: I like mature women, ass play, humiliation, and bondage too. Sometimes simultaneously! Take that, evolution.
Mature women is straightforward, older = more knowledge and capable.
Pretty much everything else you listed is about trust, so I’d say that trust is a very big thing you value in a partner, and due to humans very long time they spend dependant on parents and our community survival strategy, trust is very much a trait that is selected for.
People that are untrustworthy are unattractive, a lot of kinks primarily build on top of publicly shameful acts in private, which is effectively the ultimate trust fall exercise.
Feeling like you can trust a partner with such acts is very very positively reinforced genetically, so it becomes sexually attractive.
In short: because humans live together and make complex communities, trust is important, which means getting kinky is very sexy as it signals deep rooted trust.
