Most countries don't have this problem, but it's a bigger problem than even the US' ballooning medical costs.
I think it's less to do with the actual costs of the divorce, and more about converting one household into two. All the equity in the house gets split up, which usually gives a decent deposit for another house for each partner, but nowhere near enough to pay off the whole mortgage. Each partner needs enough rooms to host the kids during their shared custody, so a family of 4 goes from needing a single 3-bed house to needing two 3-bed houses. They need two cars, instead of being able to survive on one. If one of the partners gave up their career for the kids then there's alimony to pay. And so on. The legal bills are like icing on the cake.
The expenses of two people living together are almost the same as of one person living alone. The extra expenses are mostly for the kids (including the mortgage for the larger house). Which means that if one person has a good salary, the other can "early retire" immediately. Or if both have good salaries, they can save half of the income, and perhaps retire as soon as the kids become independent.
A divorce throws all of this out of the window.
Few people want to be completely beholden to the whims of another person for their entire lives.
I'm not arguing that people don't divorce for bad reasons, but there's also a solid reason why divorce is a good idea in many cases.
I will argue against a system where there is a lobby designed to glorify and encourage divorce and stoke marital conflict, followed by a litigation which costs around $200k between both sides to bring to completion, which ends when one side or the other runs out of money.
At that point, in most cases, the custody and financial arrangement is designed to be ridiculously complex and inequitable.