Random (possibly sophomoric) one man philosophical bullsessioning here:
I was listening to a podcast about the philosopher Derek Parfit and the Repugnant Conclusion. Now in its original form it's "For any possible population of at least ten billion people, all with a very high quality of life, there must be some much larger imaginable population whose existence, if other things are equal, would be better even though its members have lives that are barely worth living" but in the discussion I was listening to (and in most of the links I can google) folks freely replace "quality of life" and "worth living" with "happiness" - that seems to be common in the "definition" of philosophical utilitarianism
(I've heard of other similar "cranked up to 11" thought experiment paradoxes on maximizing happiness, like this smbc comic about how one in theory one INSANELY happy person could justify the misery of everyone else...)
But - like so many other things that try to operate in a reductionist way - considering "happiness" in an abstract, context free way strips it of meaning. "Happiness" should only be a goal if it's a metric of other worthy things going on! It is a byproduct of emergent properties of value, not an end unto itself. And there's a very simple (and ammenable to most folks intuitions) thought experiment to show that: it could be you could maximize your own happiness by staying coked to the gills on various drugs -- but few people would say that is a more worthy time of life than one filled with a more organic set of ups and downs.
Now, this is potentially a morally dangerous stance - you should be wary when anyone starts talking about "the worthy things of life", especially in the context of thought experiments about large populations. Like, I do believe in a universal measure of worth, a kind of absolute moral truth, but it has two important qualities: it's emergent (a property that comes out of interacting groups, not one handed down from outside our system) and it's uncertain - no one has a definite claim on the accuracy of any model of what is "True", and so any thought experiment that runs counter to common sense morality is deeply suspect.