The divorce rate has fallen because the demographics of marriage have changed

It could be - but it's also important to note that number is lower than it's ever been, not many do succeed in getting married, and only 14% of respondents had financial reasons for not being married. I think there's a lot to do with the modern zeitgeist in the "too young/not ready" and "looking for the right person" categories.

Just so you know, there isn't always a tax break for being married, unless one of the partners is making significantly less than the other or is a stay at home parent.

In many cases, you can actually save more money by filing separately, and instead of getting legally married, just become "domestic partners". Health insurance treats domestic partners just like spouses (so you can still add each other to the primary person's insurance if you want).

Many of the other "benefits" of marriage can be solved by intentionally creating a living will where you state how you want medical issues to be handled, and where you have named the other person as your benefactor if you die. You can even list your domestic partner as the benefactor on your life insurance policy.

As for kids, you don't lose your parental rights just because you aren't married. It's still your kid, and you still owe child support regardless. There are plenty of people who are divorced and have kids. Being in a domestic partnership with kids works just fine.

Honestly, I don't even know why anyone gets married these days. The laws regarding marriage in many states are so antiquated and nonsensical. A lot of the laws and protections in marriage are designed around the antiquated idea of stay-at-home moms who can't work or provide for themselves. That's not the modern world we live in anymore.

My significant other and I have been in a relationship for over 5 years now, and we have a 3 year old kid. We keep almost all of our finances completely separate (with the exception of a shared savings account just for household and childcare expenses). She makes her money, and I make mine. We track all of our shared household and childcare expenses using Splitwise, and we file our taxes separately. When we do our taxes, we figure out who gets the bigger refund that year (when filing for head of household and adding the childcare expenses), and then we split the refund difference.

Everything is totally fair, and everyone pulls their own weight in the relationship. We split all of the household duties, and we split things like childcare duties, too. For example, she watches the kiddo all day on Saturday (giving me a day off), and I watch him all day on Sunday (giving her a day off). We also play World of Warcraft together in the evenings after the kiddo has gone to bed. Life is great!

There's no logical reason why we should necessarily uphold the institution of marriage and the nuclear family as the foundational structure of society. We could all enjoy fulfilling relationships with each other and with our community's children without marriage. In fact, I'd go so far as to say that we are failing many people in society by only legitimising those relationships that are based in marriage and legal parenthood/guardianship of children.

Historically, most humans did not marry and were engaged in collective child-rearing, rather than foisting the responsibility on a single pair of parents that were either biologically or legally bound to a child. These practices only emerged with the agricultural revolution. I think it's easy to imagine that children would have a far more enriching experience of growing up if they were cared for by a larger group of people with a wider range of age, experience, skills, etc. Not to mention that it would help with the problems of children growing up in "broken" or single-parent households, where they may experience poor or insufficient care and attention due to economic hardship or parental absence.

In Germany, marriage is viewed by the state as only a legal function. You must have a civil ceremony at a government office to make your marriage legal. Religious ceremonies are not legal marriages. After the civil ceremony (if you want to) you can have a separate religious ceremony.

Many people now just do the civil ceremony and skip the religious ceremony. It was interesting to see all the couples outside the government office waiting to get married on whatever day marriages were performed.

Inheritance laws, the tax code, spousal rights, some legal protections including in the court room, property rights, and family law are keyed around marriage. There are allowances for non-matrimonial relationships, but generally it makes your life easier or your SO’s life a lot easier from a legal, inheritance and property perspective if you’re married and one of you dies. You also receive some tax advantages while you are both alive.

Put it another way, there’s a reason marriage has existed and was pervasive on every continent every human was on, even prior to the Columbian exchange. You can go against the grain and say the government has no place qualifying your relationship, but it does have some say in that and for some good reasons.