An Iranian scholar Mohammad Ali Rezaei Esfahani talked about how inheritance works in Islam. Here is a summary of his remarks:
Before Islam, women and children did not get any inheritance, because they did not fight in wars. But Islam changed that, based on what the Quran said in verse 7 of Surah An-Nisa.
Also, verse 11 of the Surah reads: “The male shall have the equal of the portion of two females.” This means that the daughter's share is the basis standard, even though the result may be that women get half of what men get.
Justice means having a fair balance in the economy. The Quran's law for inheritance also considers what people need. So in Islam, inheritance is based on justice, not equality. But some people may ask, why do men get twice as much as women?
There are some cases where women get the same amount of inheritance, or even where women get more than men. For example, when someone dies and leaves behind a daughter while his father is also alive, the father gets one-sixth and the daughter gets five-sixths.
If we look at the whole family system and think deeply, we can see that the way inheritance is divided is fair and balanced. And contrary to what some people think, women actually end up with more money than men, because women get inheritance from one side, plus marriage portion, and maintenance for life. They don't have to spend for the children.
But men, even though they get more inheritance, they have to pay for maintenance costs and marriage portion while also spend for the marriage and supply of children.
Daughters save their inheritance, but sons spend it. And if men and women got the same amount of inheritance, over time women would become rich and men would become poor. And then the economy would be unbalanced and favor women.
Some people who criticize the Quran's law for inheritance make a mistake. They confuse law with value. They think that inheritance shows how much someone is worth.
But law is not about value. Law is about regulating how people relate to each other in society. And law is based on wisdom and benefit. Especially when God makes the law, because He knows everything and He is All-Knowing. So the reason for inheritance is not about value, but about creating fairness and balance in the economy.