The yes isn't coming from a sexy alpha perspective, it's coming from a utility beta perspective. The man is useful to her, he doesn't necessarily turn her on.
All women dream about the sexy alpha male, they don't dream about the relationship man, the husband who provides and drives the kid to soccer practice. Not that there is anything wrong with that, it is just their biology.
Now if a man wants to hang around a girl enough hoping she falls in love and sleeps with him, that's his prerogative. She may make him wait and jump through some hoops. But if a James Bond comes along and he's got 24 hours before he goes to Spain, she is not making him wait.
A man wants to be a "lover", not a "provider".
Couldn't have said it better myself.
Look at the relationships that you heard about where they were "friends" and then it "just happened". Do you think these guys seem alpha to you? Do you think these guys are the kinds of guys she touches herself to on lonely nights? Or are they nice guy providers? You can certainly be one of these nice guy providers and it CAN work to get into a relationship with a girl, but it's a massive time investment on your end for a tiny chance that she decides to "select" you. You'd have to orbit a lot of women for even a chance at being "selected". And once you do, the relationship dynamic will be the kind where she bosses you around, is always angry and arguing with you, the sex is lame and infrequent and she controls it, and she is secretly cheating on you with the alpha guys.
If you want a relationship with a woman, the best position to be in is the alpha who turns her on, yet is willing to be in a relationship with her. It is difficult to pull that off in a functioning relationship though, because if you are the alpha, she will do anything she can to ensure she retains you and locks you down 100%, even if you've already given her a commitment. Your word won't be enough. She will be in constant fear and anxiety that you're going to leave or you're out there banging other women. This is where the manipulation starts. She may try to isolate you from friends, get you to marry her, demand you block exes on social media, trash talk your female friends, get you to gain weight and get out of shape, move in with you or have you move in with her, etc. Ironically, this kind of fear and anxiety make her extremely hot and turned on and sexual.
In the first scenario, she's arguing/manipulating because she's frustrated that you aren't alpha, can't provide the masculine polarity she craves, and can't turn her on the way she wants to be (though she doesn't consciously understand that this is the source of her frustration and anger - she just knows the emotions she is experiencing without the underlying reason and so if she is frustrated with you, whatever it is must be your fault). In the second scenario she's arguing with you because she is fearful and anxious that you'll leave her or cheat on her and so her motivation is to try to lock you down and ensure she has no competition. Both scenarios aren't that enjoyable but if I had to choose one I'd just the second, or simply just have short term flings.