Wow didn't know about that brothel in Europe, and I must say it's very interesting what you wrote. If I was a sociologist I would probably do a research about the preference of this men for sex doll over real women. Unfortunately, I'm not.
But if I have to take a wild guess, I'd say that's maybe because of social pressure and taboos: go to prostitutes is a major taboos because people naturally think that having to pay for having sex with another person is a loser thing, especially for men on whom social pressure about their sexuality is greater than for women (generally speaking at least); but realistic sex doll are a new thing and most important they are things, not real persons so society doesn't already wrapped its head around it and I bet that the majority of people think that using a realistic sex doll is closer to self pleasing like masturbation (that is widely accepted) than to use another human being for pleasure via payment.
About the last the last thing you've wrote, I agree on the fact that greater the interest in someone as a person = greater fun during intimacy, but I'm kind of demisexual leaning so my opinion is veeeeeeeery subjective.
A problem with sex dolls is that cost wise, and use wise, smaller is better more easy to move around and position(less heavy). But even with adult proportions(you know even small action figures can represent adults), there is the problem some find it controversial as these might be seen as childlike, so smaller cheaper dolls are fought by governments.
Smaller dolls become more problematic if they are animeish, as some say anime art style is childlike or pedophilic, even if involving adult anime characters.
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Realistically, people ask me if I'm over 18 from time to time(I can look younger or older depending on if I'm on top of my game.), even in college I've seen adult girls that look to be in their teens, as well as petite.
Now I'm of the controversial position of free speech. Nothing is truly sacred or taboo. Human body shape is public domain, and it shouldn't matter what body shape you give inanimate objects or artificial animate objects(including cg).
Unlike transexuals I aim to be transaging as well as transexual. I'm a transhumanist, and aim to become posthuman. Through the power of science or the truth or the singularity I should be able to take on not only digital but realistic avatars of any age or sex. That is I should be able to physically rejuvenate myself to the age of 12 if so desired.
BTW, it is controversial but similar to the following could be used as a VR avatar or vtuber identity. And with VR glasses or AR glasses as if really physically there it would appear