To be fair to OP, women don't have to outdo men to reject 80% men.
For example, usually women opt for men who are better than them financially. [Feel free to refute with data]
In a world where there are lots of jobs making low wages, and very few jobs where you make high income. [Feel free to refute with data]
This leaves us with 80% women earning average wage and 80% men earning average wage.
Now these 80% men are not suitable for them and women select for partners who do well financially. I've seen several papers and surveys on this, feel free to refute this with data
So, now you've 80% women aiming for 20% men who have plenty of choices and they don't want to commit nor settle.
Other than this, education and career has drastically increased the age at which women have kids.
Lots of women I know personally want to have kid - but they suffer from fertility issue mostly because most of them are in late 30s. Is this the right are to have kids? Even if it's, their body is not cooperating with them to achieve this goal.
Other than this, there is one problem that today it's very easy to leave a relationship or marriage, so most don't dream about future when future can change very fast.