Even though u/thesandbergprinciple has already brought exactly that topic up, I want to reassess it again from another angle: that of the feminine imperative.

Now don't get me wrong, the story as such is possibly made-up. Yet the reactions aren't, and here it gets interesting. Most of the reactions to that OP were mixed. A lot of people told the guy that he's settled for, that he's plan B, that she lied to him, and that he should bail (which he did). However, there was also a very vocal and very opinionated minority that was telling him that he probably makes a huge mistake (one even said explictly "I am sure you'll regret throwing away your 2 year-relationship over this"). Why did they do this?

Simple: because they had once been the girlfriend in that equation. A woman who has had a one-sided relationship with an emotionally unavailable guy (presumably above their league) and picked their plan B as their rebound relationship, only to grow attached to him over time (or so they say, you don't know how genuine their comments or how deep their feelings actually are when compared to plan A-guy). And these women said like a single person how much they love their (boring but stable and loyal) plan B-guy and how great their relationship is, totally disregarding that the woman in the OP lied on several occasions and has showed a lot red flags beyond that.

But instead of giving advice that's in the best interest of the guy who is asking (i.e. the sort of advice they would want and also need if they were in his shoes), they are giving out advice that's in the best interested of the guy's girlfriend (i.e. the advice they would want him to have if they were in her shoes). This, dear sirs and madams, is what we mean when talking about "solipsism": they can't separate the situation from their own, and they fill in pretty much every blank (and even some non-blanks) with their own experiences (which of course have an ego-bias insofar as they only ascribe the purest of intentions to themselves). As a result, they don't see it as a problem the guy has, but see is as the problem they would have if their partner had asked the same question OP had.

However, what they're defending and hoping to preserve is ultimately a one-sided relationship where the guy compromises for the right of calling her a girlfriend, while she is the one who can make the demands and set the boundaries. If I should evaluate that relationship, I would say that it is a fundamentally lopsided one, where one party (the guy) is - or rather: was - more in love with the other. Yet plenty of women/feminists/feminist women would consider this a perfect example of a great and equal equal relationship simply because the woman isn't pressured to do stuff she doesn't want and the guy isn't willing to walk (until he found out that he was lied to, that is). And mind you, this story has been partial for the guy. Had it been told from a neutral perspective, it would probably have been the majority who thought like that.

This is the feminine imperative: taking on the female perspective by default. Because the problem with modern relationship advice is that it largely works along these lines: it's not only gynocentric but quite often also written from the perspective of a woman who has exactly the red flag-trait she is commenting on (the woman who takes up the cudgel for her older sisters is usually over 40 herself, the one who touts the qualities of single moms usually has children but no partner herself, the one who praises "experienced women" (or alternatively praises how genuine reformed sluts are) usually took advantage of the hookup culture, the one who defends nice guys finishing last is usually one who tried to get alphas in her 20s and is looking to (or already did) settle down in her 30s etc.), justifying their own poor life choices, bemoaning the injustice of the dating scene or telling men men to suck up their insecurities and don't be so narrow-minded. In other words, "Sailer's Law of Female Journalism" (“The most heartfelt articles by female journalists tend to be demands that social values be overturned in order that, Come the Revolution, the journalist herself will be considered hotter-looking.”), and basically a huge blindsighting effort on behalf of women who are on some level at a disadvantage when it comes to dating or relationships (or rather: less privileged on it than they used to be when younger).

This is the beef (well, one beef) I have with typically bluepill positions. They try to paint decidedly unequal and non-egalitarian relationship as equal simply because their main selling point is the absence of male predominance, and also try to promote equal and privileged relationships for people (of the female gender, that is) who would have a hard (or at least harder) time getting into one without a supporting narrative. Which is also why I can't get rid off that vaguely Orwellian feeling when BP talks about "equal relationships".