And yet, so many women go completely sexually unsatisfied in their relationships. Maybe husband has ED. Maybe husband is cheating or has a porn addiction. Maybe he's simply terrible in bed. You've made this out to be a gendered issue, when in fact, it is not. So does your comment stand for women as well? Should husbands not be surprised when they are cheated on or dumped, if they aren't providing an adequate sexual experience?

As far as assets:

The one GLARING problem with your comparison is that until very recently, women were expected to stay in the home - and in fact couldn't even have assets in their name. The divorce laws were created so that women could leave unhappy/unhealthy/toxic/abusive marriages. In other words, have some say over their own lives, whereas in previous generations women were stuck basically regardless.

In addition, when the wife does stay home/is the primary parent, she either doesn't have a career at all or hers is stunted in order to raise your children. So a fair division of assets when she has provided you the freedom to enhance your career while she takes care of everything else - is 50/50 of the marital assets. And if she will continue to be the primary parent (which is usually the case), it is also your job to make sure the kids are financially provided for because she is in a worse financial position for having agreed to take on the role of primary parent.

Maybe there will be a time in the future when these won't be false equivalents (I certainly hope so!), but for now they are. Especially because women who make more/have more assets are held to the same standard.

And if you are willingly sharing those assets by getting married and allowing her to be your free domestic baby-making labor, then you've implied willingness to share the fruits of your labor as well.