Like everything in life, there are pros and cons to every situation. Utopia is as big a stretch as congress agreeing or the Cowboys winning a Super Bowl as long as JJones is still taking breaths.
Certainly a loving and caring partnership (marriage not necessary) with the person of your gender preference, with similar values and interests, and a matching sexual drive is by far the best option. Statistics bear out that few ever get there. Personally, I think our societal mandate towards monogamy hinders that substantially.
Speaking solely from a sexual perspective (and this is only one part of the human interactive equation), sometimes we want hot monkey-love scrogging and sometimes we want passionate loving. And the comparisons of wants and needs differing at various times could go on forever--friendship, companionship, nurturing, procreation, etc.
It is highly unlikely that you can get all of those needs met by a partner/spouse or a provider. So I circle back to monogamy and my disdain for that. Again, using sex as the jumping off point, we all, at least from time to time, want something "different"--bigger, smaller, faster, slower, taller, shorter, tighter, softer, skinnier, prettier, darker, stronger, younger, older--again the comparisons could go on and on and on.
Not that I am suggesting cheating is the answer--although on this board, in some way or form, most reading this could be considered a cheater...or cheatee. Cheating hurts--whether in a relationship or business or playing a game. I just think that we have been programmed for far too long that there is this one way things have to be to provide happiness. And it goes against our basic nature as nothing more than intelligent (some much more than others) animals.
So you get married and then you get bored or you don't get married and you get lonely. And you make decisions that get people hurt--emotionally, physically, financially. To me it is not relevant the CPF (cost per fuck) factor but more the overall happiness factor. No one person, just like no one drug or drink or food or movie genre or car, can meet all your needs.
If we were honest about this, as a society, we all would find ourselves much more fulfilled. But then what do I know...I too am only human!