This is one of those areas where there is more than one path, and not all of them are good, or honest, or beneficial.
Of course the open relationship has more and more adherents as communities in general have more abundance and necessities require less labor. It also seems more appropriate as man starts living longer. Being with one person seems doable when its only 40 years. It seems silly at 100 years.
However, an open relationship model does not allow for deep, intimate relationships. You just don't have the time, nor the desire to plumb the depths of one person when you split your focus.
Also, there is the thoughts of raising a family. Men want to fuck. Women want to have babies. The problem comes about when a woman wants an open relationship and babies. This destroys children like nothing else. The prisons are full of children of single mothers. So, if you want to have children, you need a stable relationship to bring them into.
So, i really don't know if one path is better than any other. But, i do feel that society had better get its act together... for the children.
I think there is tremendous value in just allowing a bond of trust to for without strict rules about how relationships have to be. It doesn’t mean taking advantage of every freedom, but I find my relationships are much stronger because neither person is exerting pressure on the other to stay and yet both people stay. I think when most people imagine this kind of freedom they imagine everyone going around fucking everything with legs, when that is not the case for many mature adults. Are we truly mature adults though? We can do our best but our upbringings will still influence us.
Responsibility to our own desires doesn’t mean disregarding others. When we are truly in an abundance mentality, we will not be happy to leave someone struggling with our children. Once again this is all very idealistic stuff and as far as I’m concerned it’s judt a direction to move in, not something we should force on ourselves or others.