You are in fact very right, but there is one critical issue here. If we are talking about marriage. Culturally there is a "lifespan" of value to both genders. A Man's valuable lifespan can be well over 20 years, from age 20 all the way to age 40.While a woman's valuable lifespan maybe only less than 10 years, from 20 to 30.

This is because of the "stake" people are seeking when looking for a marriage between genders. Women are seeking wealth, social status, personality and whatever it may take to maintain a stable marriage ( family). While men, in most cases, are looking for prettiness, good-looking or whatever superficial. This kind of value lifespan and marriage purpose mismatch is the whole problem of marriage issues in China.

A divorced, less pretty (compare to those in 20s), mid-aged woman is very hard to find another marriage. Even if they did not even marry before, it is still hard for them. A lot of women in China who are well-educated, well-paid, in their 30s still have problems in finding partners (This is what Chinese society called sheng nu, or "women that left behind":https://en.wikipedia.org/wiki/Sheng_nu).

Statistically speaking, women are indeed more than men, but the mating process is not statistic.