I see two issues here:
1) All women have some inherent level of insecurity that never gets better as they get older. In contrast, men's insecurity improves over time as we address our weaknesses in life and learn to ignore the things that we can't change. Women can try to do the same thing, but they never really feel it the way that a man does.
2) Women are more realistic with relationships than most guys realize. They have an inherent ability to quickly categorize a guy as player or provider (on a spectrum, not absolute) and decide if they can work with the guy.
So, my guess is that your friend has lower self-esteem (which she may be able to hide very well) while she has a somewhat realistic view about her chances for a worthwhile relationship with certain men.
With regards to chicks ghosting, it's not a vindictive thing. Women auto-reject when they don't see a reasonable chance of things working. They might sleep with a guy once or twice just to get him out of their system (they suffer from the same "what if" regrets that guys do). Then, they'll ghost him because they don't want to try to "logically" explain something that they feel a guy should inherently understand.
As a guy, you need to figure out what her perception of you is relative to her. If she acts like she's nervous about offending you, it's an obvious sign that she thinks very-highly of you. You should be building her confidence and bringing her up to your level.
I read so many posts on this board and others about women being random, vindictive, agents of chaos, etc. I really don't buy any of it. Women are very shrewd about relationships. As a guy, you should always try to understand what's in it for her by assessing where she is in life and where she's going (which can change even on a short-term basis or when they're on vacation). A single-mom looking for some help has completely different goals than a recently-divorced 40ish woman who is in her "fear of missing out phase".
Man you might be right. I may have to re evaluate my theory. Let me offer a couple counter points though.
1.) Women routinely say " I dont know why I even slept with him/ dated him". They say this months after they stop dealing with the guy. Isn't this evidence of chaos?
2.) Women often will keep a guy as a beta orbiter then develop latent jealous feelings over him when he has sex with her friend. These are conflicting emotions. Isn't this evidence of chaos?
3.) Women will fall out of "love" with a man years into the relationship for no identifiable reason. More chaos.
4.) Women will often like a guy that is lesser value, but friend zone higher value guys. Then smash an ugly guy, then smash a hot guy etc...seemingly random behavior.
5.) Women often display cognitive dissonance and cope mechanisms to avoid personal accountability. For example the fat acceptance movement. Chaos right?
6.) They struggle to understand simple contradictions and hypocrisies of feminist talking points. For example, they want equal pay....yet they want men to make more money. Is this not chaos?
7.) Their attraction meter is visceral. Its not a logical evaluation of objective reality. Visceral attraction is chaotic.
Maybe my logic is off brotha. I just dont notice any consistency in their behaviors. All I hear is alot of fuzzy " I dont know why I did that...umm" when I talk to them.