Almost all couples in which the man treated the woman well, because the man is healthy and not psychopathic, or even beta, have broken up due to lack of "desire" or because "the love is over".
Because the man gets comfortable and stops improving.
Alot of men think once they get the girlfriend or wife the game is over, that they can put their feet up and relax as they always a warm place to put it at night.
Men stop doing the things that attracted the woman to him in the first place and she starts to wonder "was it all an act to get sex?" and starts to think she can do better.
Yet women aren't innocent in this either, because once they allow the man to get comfortable in the relationship,
women do the "pullback". They start acting differently, talking back, having conditions for sex, etc. They want to see "is he going to change his behavior because he can't get sex from any other woman, or is he going to act the same way and not let it bother him?"
If the man starts acting differently from what he did in the first place, then she knows she's got a Beta Sucker and will eventually crush him,
It's also why LTR don't make sense in 2024. Back when, if a woman disrespected or left or divorced a man, she would be shamed to no end by society. Now, its been changed to
"happy wife, happy life."
It's tough out there.