I believe in vitro fertilization but there are reasons why a woman might choose to ignore that option
1. It's not 100% guarantee. In fact, the older you get, the less likelihood of success. For women who have tried it without a positive result, they would be less inclined to tray again. This also applies to older women too
2. Religious/ethical reasons. Some religious sects are against assisted reproduction. If a woman is a member of those sects or share their ethics, she would not consider in vitro fertilization
3. Fear of failure. This is one reason why most people don't do most things in life and women seeking children are no exception. They could feel like they can't survive a negative results so they are better not trying
Although in vitro fertilization is a breakthrough in the field of health, embryology and biology in general because of its clear advantages, it is not always the answer to "I can not get pregnant." You have to evaluate the factors why women can not get pregnant.
In the view of an older woman who can not get pregnant there are several factors.
Amount of available ovules and woman's physiology.
In vitro fertilization gives you the advantage of choosing the most suitable or fittest gametes (both ovules and spermatozoa), that is, stronger and stronger. This allows to generate a healthy and resistant embryo and fetus that is more resistant to a complicated pregnancy. It also makes pregnancy easier for women by decreasing physiological complications of the fetus.
But older women have other complications, an example of this is the number of ovules available. That's right, these are not unlimited, the ovules end with time, because at one point they stop being generated and a total remains, which is lost in menstruation throughout life. Without a woman's eggs, you can not do in vitro fertilization (unless you want to have another woman's child, acting only as a rented belly).
Also the physiological conditions are important. With age, the woman's uterus may lose resistance, being unfit for the development of the embryo.
After 40 years of age, the woman suffers a decline that decreases her fertilization rate. With in vitro fertilization you can help get pregnant but the integrity of your own eggs can interfere. For this reason, ovodonation is recommended; that the woman receives cryopreserved oocytes which may be characteristic of some moment of her fertility, or may be donated by another woman. This increases the ability to be successfully fertilized.