Easy, men give women attention because they want sex. Women, knowing that men want sex, select for the most attractive male(s).
In the olden days, it was based off prestige, either you brought food for the village and got pussy,
or your genes died out. Women would select for the strongest male, ensuring survival of both mother and offspring.
Men had to compete for pussy, or rape. In other words, if a guy wanted a girl, he could not discriminate. Whereas women, the prize, could.
In the modern world, with social media and all, it's based on two things:
1. Because most of us in the west no longer need to fight for survival, especially young people, survival skills no longer matter, or help you get a girl. In school, girls learn, like many thousands of years ago, that men want sex. Except now, you can't be a 1/10 male and bring home a lion, then impregnate all the girls in the school. If you kill a lion and bring it to your high school in an attempt to attract a female mating partner, you'll be ridiculed.
2. So, what happens, guys still want girls, and girls still get to choose which guys they fuck. It's still a contest, and most men still lose, but the thing that gets you pussy is different now. It's all about looks, and appeal.
As women get older, they realize that high school isn't real life, they can't just select for looks and personality. So they start looking for Chad that makes money. Most Chad's, having grown up being showered in pussy, are spoiled brats that do not succeed financially. What do women do? Settle for betabuxx and cheat on him with Chad.
TLDR: Women are more choosy because that just how nature intended things to be. Survival of the fittest. Men want sex, but women can only have sex with so many men, they select for the best quality mate - and what type of male is the best quality mate? The definition has shifted throughout that ages, it is currently, and will likely continue to be Chad.
