OP, marriage doesnt get you anything else that you couldnt get without a ring.
NEVER invite the law into your relationship in a western society more then the bare minimum neccessarry. It will limit your options in best case and fvck your life over in worst case.
Even talking about kids, i wouldnt go into marriage again. You have no rights anyway at family courts, what she says goes for the kids.
The single one and only thing that mathers in a LTR (marriage, if you are insane enough) is that she keeps thinking you are the best that she can get and makes the effort to keep you (keep your belly full and your balls empty) /is afraid to lose you (#dreadgame).
And this is why people recommend taking women a lvl or two below your own for LTR. When women believe that you are the prize, allmost everything goes and it makes your life so much more enjoyable.
That is pretty sad.
Duty sex instead of sex by desire. But that comes with the territory I guess.
From the male perspective:
Well..... lets be real, every pvssy gets old after you had it for more or less years. Even if its steak-quality, "eating steak every day" for the rest of your life sucks and at some point you´d take a McD burger over the steak just for the sake of having something different.
From the female perspective:
A lot of men stop being the men they were when the woman met them. Either they let themselves go or they let themselves get turned into a doormat by their wifes and therfore become unatractive/stop getting her wet. No wonder there is no sex for the average frustrated chump.