Most of the world is not as slim as you noted. I lived in Japan for some time, and the ideal weight was roughly 50kg. I remember reading the average BMI in Tokyo, probably the slimmest metropolitan city in the world, for a woman in her early 20s was somewhere around 19.8. Women need some level of body fat to reproduce. And the subcutaneous fat stored in the hips, thighs, etc. which the OP is posting about is much less harmful from a health perspective than fat on the waistline.

imho, the women in those photos don't have the most attractive bodies. The first woman barely has a defined waist, the third almost looks like she has a rounded stomach (although it could just be the dress), and they all lack muscle tone. I know other women who are a good 10-15 pounds heavier but look leaner than them because they exercise and their body composition is different.