The truest cost a woman pays for being with a man she does not deem not only greater than her, but greater than the greatest man she's ever known, is the ugliness that seeps into and corrodes her soul in settling for him. She cannot help but become ugly with him, even if she wants to pragmatically build something with him, because she bears the imprint of a man's soul on her greater than him.
Her propensity to resent then outpaces her capacity to appreciate. For as much as she can in her warmth appreciate a lesser man trying his best for her, appreciation is not attraction but recognition of kindness. Appreciation is necessary, but not sufficient. It does not compel or bind in so much as it indebted, for guilt alone is no basis for devotion.
When a woman's soul is marked by a man greater than the man she's with, she compares every aspect of the current man to her best known man, and sees all areas in which he falls short. And in being so acutely aware of what he cannot do, where he is inferior, where he is less compelling, be it less nuanced, less aggressive, less intuitive - whatever it is - she will feel a void, and that void will drive her in her dissatisfaction to lord over him, and in doing so emasculate him, thereby rendering him defeated and her ugly, making for a most unholy and truly losing circumstance for each.
It is horrible for the woman, because she will never know the true satisfaction of being fully, actively and completely owned, which is her deepest spiritual need as a woman (and what fully enables and unlocks her capacity to be beautiful in her devotion). And it is horrible for the man, because he knows no dignity and receives no devotion, for even if he is not directly and explicitly compared to the ghost, he will feel that man's presence in the lack that "his" woman gives to him, because in reality, she is not his - only with him - and these are very different things, because irrespective of who she is actually with, she only truly belongs to the man who took her soul, and that is not him.
The end result for each then is a very pragmatic, but ultimately soulless union doomed to failure. If it does not collapse, it lives without truly living on little more than convenience, and in the most pathetic of cases - perhaps fear of loneliness, because in truth what they have is not beautiful, but perversion born from mutual desperation. Unfortunately, amongst the west I think they have to a degree normalized such unions. Truly, a monastic life where one dedicates themselves to study, charity, the reverence of God or all such things would be truer, purer and more beautiful than the romantic carcass of whatever this sterile charade passes for.
The measure of his soul is defined by the degree and depth she was influenced and felt possessed by what she considers her defining man. The later man could be objectively better looking, richer, smarter etc - wouldn't matter. It's about individual soul capture, not broad market appeal.
The thing about the "defining man" is he tends to be the axis by which she defines her femininity, because he is her standard and access point to the masculine and how she relates to it. A woman is a maiden, as in, coming into her formative womanhood from her teenage years up until around say 23. The capacity to be imprinted upon is far more prominent here, than later on when survival scripts and ego crystallisation are more prominent/rigidly self-defining, and pairbond capacity has weakened.
Essentially, whatever man authored her womanhood owns her, and is the rubric by which she compares you, and defines herself.
For me, the only solution, from a man’s perspective, is to walk away. And you must do this early, very early in fact, before you start counting your investments, financial, emotional, and otherwise, and convincing yourself to stay simply because of what you’ve already poured in. That is the trap, and it has swallowed many men whole.
You may ask: how will you know the kind of woman whose soul is already tethered to another man, one you can never compete with, one you can never retrieve her from?
The answer is simpler than you think: it shows in her reactions to everyday life. A woman bound elsewhere will, from time to time, compare you to the man her soul belongs to. The comparison might be subtle; a word, a sigh, a half-formed sentence; or it might be glaring, like thunder cracking through a silent night. But if you are observant, you will catch it. And when you do, you must run for your life.
Because here is the bitter truth: no matter what you do, you will never measure up. Not because you are lacking, but because she is elsewhere. Her body may be present, her laughter may be present, her warmth may even be present, but her soul is not yours; it belongs to another. And when a woman’s soul is tethered to another, you will always be the moon at best, a shadow at worst, but never the sun.