Humans are terrible at figuring out what others want. I think one of our worst habits is projecting what we want on others, trying to fulfill what we want then not understanding why we don't succeed. This is what the red pill breaks down, it breaks down the barrier in the mind and truly understand what others want, and often it's horrible. The rest of this will generally focus on female change over the past 30+ years but men are very guilty of this, look at all the nice guys trying to figure out why a woman won't date or sleep with them.

Success
This is generally job and money, but it doesn't have to be, power slides in here as well. Women desire successful men, insanely so. Many women will easily spread legs for an ugly successful man if he is successful enough. Over the past few decades women have been riding that success train, building their career. I saw this with my sister, she is very successful in her career but she's also is alone and almost 40, despite her desire to have a family. Success doesn't matter as much to men, certainly not as much as it does to women. To compound that, the more successful the man, the less success of the woman matters. This is made worse by the fact that since success women view success as so important, they view anyone that is lower on the success tree and not worthy.

So in short the more successful a woman becomes the higher their success target becomes, and thus less their actual success means to their desired man. And this boggles their mind, notice how so many "where are all the good men" articles start with "she's successful" not understanding just how very little that matters.

Desirability
When a woman brings her man around to her friends, she wants all her friends to want him. She wants to show him off, and say "look I know you want him, but he's mine and you can't have him". It's that power of knowing that she has what others want. If you take the same man, and convince a woman that no one wants him, vs everyone wants him her perspective changes it's actually pretty bizarre but I believe this is due to their desire to be approved by the group. This is also why compliments from an undesirable man is literally rape to a woman. She is terrified that if her friends/social pecking order find out that someone so low likes her, it will lower her value and social standing.

Social media breaks this mindset even more, because in her head all these desperate simps feeding her likes and money are all super mega chads fawning over her. There has to be some level of disconnect there on her part, because if a woman actually sat in a room with all her instagram followers she would panic and run from all the undesirable men (in her perspective).

This is also why you see women reach those insanely high sex number counts, it doesn't matter if it's easier or not if the woman doesn't want the sex. You will see a woman who is a 7, get tossed around by a 100 guys that are all 9+ then she doesn't understand why no 9+ wants to marry her. In her mind she is desired by all these 9's because look at how much sex she had, so you should see that she is clearly desirable. Of course this isn't how men work, and women just don't understand that.

There are some other items that often get projected like desire for emotional expression or support etc.. but really these are the 2 big ones that have altered our society greatly in recent years.