Starter wife - a woman who invests in a man (by having sex when he wants, being emotionally available, doing the majority of the cooking/cleaning, etc.) while he's still "up and coming" and getting his life together but who gets replaced by his preference once he's established

Forever girlfriend - a woman who does the above but is not married to the man

The best dating strategy to avoid being used like this by men who don't actually want you is to make them invest and pursue you rather than the other way around. By "make them" I don't mean explicitly force or encourage; I mean to simply not engage with them if they don't. The reason I think this is the best strategy to weed out men who feel lukewarm about you at best is because, when people have to spend money on something or otherwise expend effort to get it, they are forced to look in the mirror and ask themselves if they really want it - and if so, how badly. This strategy is not foolproof; some men will invest even if they don't intend to stick around. However, it's far better than nothing and reduces your chances of spending time, energy, and money trying to be with guys who don't see you as more than " a fuck."

I also think it's best to refrain from performing any domestic labor for a man (e.g. cooking, cleaning, laundry) until it's reasonably certain your his preference and not his placeholder. I'm not implying it's the woman's job to do domestic labor; rather, I say this because I think it helps avoid pain/regret in the event that a man didn't truly value you and leaves you for his ideal woman. At least if that happens you didn't sacrifice time you could have spent investing in your education or career to launder his dirty socks. When it comes to sex, I believe if a woman genuinely wants casual sex and doesn't mind being ghosted, then more power to her. However, I think that if women want more than this, they should refrain from having sex until men have proven they are, first and foremost, safe and respectful and, secondly, genuinely interested in the women.

Due to evolution, women tend to be choosy in selecting mates because they get pregnant for nine months, give birth, breastfeed, and raise kids (I mean this descriptively, not prescriptively). They're also generally smaller, less muscular, and therefore more physically vulnerable. Men tend to simply want to spread their seed anywhere they can because of how women are so picky (i.e. sex is scarce for men) and because it costs them nothing - unlike how much it costs women to reproduce. This dynamic has been beneficial for helping the population of humans boom across the planet over the past few millennia, so it's not "evil." However, I think it's important to realize that men and women tend to operate somewhat differently in mating.

Broadly speaking if a woman chooses to have sex with a man, it tends to mean he passed through many of her filters and meets a relatively high standard for her; if a man chooses to have sex with a woman, it merely means she was available. Conversely, if a man chooses to open up emotionally to a woman and to invest effort and money/resources in her, it tends to mean she is remarkably special to him and stands out from the rest of the women on the planet.

My conclusion is that it's far better for women to only engage romantically/sexually with men who pursue and invest in them. I think it generally takes longer to find a man employing this strategy, but it beats the alternative of being either a divorcee and/or single mother or neglected in a relationship and possible cheated on down the line.