The idea is simple - women are heavily influenced by the perceived desirability of a man to other women. If she sees that other women want you, something switches on that no amount of game, looks, or status can replicate on its own. It bypasses the logical vetting process entirely. You don't get interviewed. You get pursued.

Pre-selection is real and it operates completely below conscious thought - She wasn't sitting there running the logic. A hotter, younger woman showed up, paid attention to a man she'd written off thirty seconds earlier, and something ancient took over. Millions of years of evolution crammed into one pathetic 180 degree pivot at a beer festival.

Human brains are lazy and take shortcuts whenever possible.

Women aren't as visual as men, and determining if a man is worthy of spreading her legs is for is more mental work for them than our determination if a woman passes the boner test. Note that I'm talking about fucking, not commitment or any of that. Throughout human existence until the invention of the birth control pill, uncommitted sex was a huge risk for women, so the threshold was high. This is mostly instinct and they can't help it without a lot of effort.

If another woman has already done the work of determining that a particular man is worthy, it's sometimes easier to try to poach him than to figure out a whole new man. Even better if multiple other women have done the work. That's why so many music stars who are total uggos still have throngs of women in the audience just hoping to get backstage.

It's why some women, when they see my wedding ring, try even harder to get me interested.

It's why so many women mate poach compared to men (that, and they don't have the threat of violence at the same level we do).

This woman equates fuckboi with "extremely good-looking", which is quite subjective. Fuck bois are fuck bois because they have an abundance mindset and plenty of options and plenty of experience. Good looks might help, but only a little bit.

"Having lots of options doesn't mean being a degenerate"...you mean degenerate as in having FWBs left and right? Like you back in 2013?

"They have no reason to lie...." Hot or not, all men have to lie in order to get into your pants that casually. You wouldn't want to hear the unfiltered truth. You think Henry Cavill gets laid simply by asking women "Wont sum fuk, luv?" Autistic dorks wouldn't even know how to lie effectively. They would probably just take everything the woman says literally (and get duly punished) or just skip the whole bogus show and explicitly pay for sex.

"My brother is extremely good-looking, He's always in a relationship". With many different women, I suppose? In the end, how is the outcome any different had he merely smashed and dashed "dishonestly"? He will probably still be exploring his many options in his 40s, whilst the women he leaves behind will be desperately salvaging some eggz. Your brother is

She claims that fuckbois are traumatized (by whom, I wonder?)...and in turn blames fuckbois for traumatizing her into freezing her eggs. So whose fault is it, if you go back along the Wicked Chain of Trauma?

"He was a great guy actually"...then why didn't you choose to get impregnated by him instead of missing out and now complaining about unfaithful men who complain about low birth rates?

How could she have arrived to all these laughably wrong and incoherent conclusions? Anything to do with giant hamsters, maybe?...

I'm going to give you the answers you need rather than the answers you asked for.

1) you are way too hung up on this one particular woman. Oneitis is bad, even if it's for your wife of several years. Oneitis is even worse when it's for a woman you haven't even fucked.

2) you'll almost never know why any one particular woman won't fuck you. They rarely know themselves, and they're rarely honest about it even when they do know.

3) it doesn't matter why any one particular woman won't fuck you. Escalate towards sex. If she rejects you, next.

4) you can be Chad and still experience a 70%+ rejection rate. Getting mostly rejections is just the male experience.

none of this stuff is about how to get any one particular woman. It's about becoming a more fuckable man to increase your odds with all women.

And more, but that's the gist at the start.