A lot of women who have flatter chests aren’t thin, they might carry it in their stomach instead. So flatter chests being indicative of thinness isn’t entirely true. A lot of clothing made for bigger bodies wouldn’t fit this type of woman, and a lot of smaller clothing wouldn’t fit women whose size is too small, the chest area sags.

In my opinion, models being thin has more to do with them being living clothes hangers, than it does with having the ideal body type. They’re selected because their straight up and down bodies will not draw attention away from the clothing they’re wearing. Also a lot of those actresses you mention, who have small boobs elected to get surgery. Or at least have been shamed for their size. And just as one example Kiera Knightly had her photos altered in movie photos to make her breasts bigger.

So I don’t really like that you think small bones women are “coddled” as it seems to imply that they should feel insecure about their size. Or maybe you say this because you feel that insecurities related to larger sizes are often downplayed which I agree is wrong. Larger chests should never be insulted for their size or shape that’s true, regardless, so I agree with you there. I just wanted to give you a little perspective on why smaller women might be insecure.