I will take a different view here. As an older woman, I see where these things came about.
Many marriages at the turn of the last century were more so "business" arrangements through family and friends. As such each side brought certain things to the wedding table (jewelry/money, a business or a title) and to make that the items owned prior to the marriage would be returned should something happen.
Fast forward there are states in the United States are joint community property states which means both own everything. There are also states that don't state that you own everything. Here is where a lot of the things get cloudy. Anything purchased or acquired during the marriage is jointly owned so this is where a lot of the fighting comes into play. Yes the children of the marriage should be protected and money possibly put into trusts so that there is something for them at age 18 or 22.
The main thing that comes to my mind is the medical student who marries while in college, sets up a practice, becomes successful and divorces the first wife for a second. So protect yourself at all costs even if you don't have anything right now but you do accumulate "stuff" as you live together.
Again communication is the way to go especially when you are calm.
The other S.
PS No one wants to think of divorce but it does happen. We don't live in a fairy tale setting - it's call the real world which throws all kinds of curve balls at you.