Why is it not a good idea to raise the age of marriage for women from 18 to 21?

Why is it not a good idea to raise the age of marriage for women from 18 to 21?

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Upto 30% of women in India were married before the age of 18, despite the fact that the legal age was set at 18 years in 1978.
This conclusively proves that the law is not a deterrent against child marriage.
Child marriage is not always due to lack of awareness. It is more often out of convivence, out of concern for the safety of the child, or because of societal pressures.In families/ communities where women are not encouraged to go out to work, there is little to be gained by educating a girl beyond a certain level.
Such girls are married off as soon as a suitable groom is found.In households where both parents engage in labour, even if the girl is sent to high school, she is home alone for a few hours every day after school. Parents perceive this as a risk, and get the girl married off.In many communities, traditional livelihoods require a woman to assist her husband in a part of the livelihood process. In such communities, girls are necessarily married off early (sometimes even as early as 14).Once a girl attains puberty, her "safety" becomes of prime concern to the family. If the family suspects she may be in a relationship, or that someone "unsuitable" is interested in her, she is typically married off to the first many the family can find.Child marriage is not, however, merely a product of poverty.
Even in "well to do" and "well placed" families if a suitable match is found, the girl is engaged to be married, and the wedding solemnised as soon as she turns 18.All of this ensures that the rate of "child marriage" in India is between 27% (UNICEF) to 47% (ICRW), despite the fact that the legal age of marriage was set at 18 more than 2 generations ago.What, then will happen if the legal age is raised to 21?

The percentage of women being married before legal age will shoot up.
Assuming a family allows the girl to study upto Class XII, she will graduate high school at the age of 17/ 18. What after that?
Most families do not want their girls to travel long distances either to work or to go to college, so she will be kept at home for 3 years.OR, she will be married off. Regardless of what the law says.If the law refuses to recognise a union conducted before legal age, then the "child-bride" will not have any legal rights in her marital home. She is the one who will suffer.If the law continues to recognise such unions, then there is little point in bringing in such a law.What then is the solution?

Education
Awareness
Empowerment
What is needed is to work at the community level to create awareness on why child marriage is not desirable both from the health perspective and from a social perspective.Once a community recognises that a woman is as capable as a man in creating economic value, she will no longer be seen as a burden which is to be set down at the earliest possible.
Once this happens, the age of marriage will automatically go up.
History has shown that the law alone has not been enough to deter child marriage. Change only happens when the community is educated and empowered.Tilak exemplifies this conundrum. He opposed raising the legal age of marriage to 14, because he did not want the law to "meddle" in personal life. However, he ensured that his own daughters were not married before the age of 16.Before we raise the legal age of marriage for girls, let us first ensure that the existing law is followed.