I've also spent mental energy on this, about 4-5 years, and recently I've been reaching a conclusion (in a great walkabout about AI, ethics, and the meaning of everything).

My conclusion: individual satisfaction is bounded, as long as we have bounded brains. First I should mention that the best principle I've found to underlie life is that we should maximize or optimize some kind of experience of consciousness, for every conscious entity. It's hard to define precisely what that entails, but we have quite good intuition: your life should be rich in activity, in interaction with others, in learning, in thought, in seeing, hearing, thinking; of course, not so rich as to be overwhelming and collapse the whole thing or leave us unable to digest or grasp or understand (at least a part of) what we're experiencing. I don't claim to be completely original: Wilheim von Humboldt for me is one of the great thinkers of conscious motivation (he lived in the 18th century).

"I am more and more convinced that our happiness or unhappiness depends far more on the way we meet the events of life, than on the nature of those events themselves." -- WvH

Being clear: what matters is not the experiences themselves, i.e. the input/output, but what the various consciousness apprehend. What goes on in your brain. It doesn't matter you're at the most beautiful beach in the most beautiful sunset behaving joyfully and peacefully if internally you're depressed or in despair.

"The true end of Man, or that which is prescribed by the eternal and immutable dictates of reason, and not suggested by vague and transient desires, is the highest and most harmonious development of his powers to a complete and consistent whole." -- WvH

You can only make an individual so complete, so harmonious with itself. Our brains have about 100 billion neurons, i.e. a finite number, and there's only so much you can activate those connections. Really the goal is not with any single individual -- our goal should be with every conscious being. That's why we should not plan individually, we should plan as a society. A billionaire can only get so happy -- he can keep linearly stacking jet skis and race cars and yatchs but his happiness won't follow (linearly). We should realize we are all part of a society, as a whole, and ideally be completely indifferent among individuals (i.e. everyone deserves as much happiness as we can collectively get them).

In other words, we should take the Golden Rule literally. (of course, in practice, not everyone can be responsible for every other individual, but it should be our ultimate guiding principle, really, as individuals and society, unmistakably): every conscious being has the same value to yourself as yourself.

Because individual satisfaction is bounded, this allows maximizing the practically unbounded (because of almost unbounded entity numbers) satisfaction of society as a whole, currently about 8 billion individuals. We need to move past egoism. I don't think an egoistical civilization, as was Western Society for much of the 20th century, can reliably go much further than we've come (see: climate change, rising political instability, fluctuating inequality, stagnating quality of life).

I'm not arguing for any political system, I'm arguing for a cultural-social-technological outlook of the entire society. I'd label it 'Universalism' (but that's taken), so perhaps 'Conscious Universalism', or 'Concious value universalism'.

That's how we move our entire civilization forward, achieve better political stability, how we're able to tackle mega projects like engineering the climate and rethinking our global supply chain, how we can allocate massive resources to space exploration, space colonization, prevention of extinction events (like asteroid impacts, etc.), how we move definitely past threat of nuclear annihilation (a nuclear conflict, still not completely out of imagination, could perhaps still collapse society).

How to do it? I think part of it is simply enlightenment, discussion, writing and reading; the other is indeed recreating our institutions, including our economic and political systems (focused around this goal).

This century is when we decide whether we become the Borg or the Federation. Cylon or Human. Dalek or Doctor. (or just slowly collapse... hopefully not; we have potential)