Carlyn, this article raises so many responses.
First, as to 19th century mistresses, I'm sure that you know the famous exchange between Edward VII and his mistress Lillie Langtree. Edward: "I've spent enough on you to build a battleship." Lillie: "And you've spent enough in me to float one."
Also, when as Prince of Wales he visited Paris and met 'La plus grande putain de Paris'. When he entered the room she turned her back to him, bent over and lifted her skirts so that she could "present her best feature"
The English equivalent was 'The Toast of the Town'. Toast being an 18th century slang word for a prostitute.
As to Kim Kardashian she is not very attractive. She looks grotesque.
And as you indicate feminine beauty is often in the eye of the beholder. In my case I have been amused by how it has changed over the years. When I was 20, I would say that about 15% of the women that I saw were very attractive. By the time I hit my 50s I would say that 85% of the women that I saw were very attractive.
Finally, let me state categorically that there is no correlation whatsoever between a woman's looks and what she will be like in bed, and it is the latter that is far and away more important. I can assure you that being in bed with two somewhat overweight middle-aged women is a far more satisfying experience than being in bed with a Playboy playmate of the month. At $2,500 a time the only thing the premium buys one is boasting rights, it does not buy better sex.