Ultimately, everything comes down to happiness and suffering.
The utilitarians were right.
If you ask someone “why ought you to do this?”,
they will almost always eventually reach the point of saying
“because it increases happiness or reduces suffering”.
For me, happiness and suffering are unlike any other facts about the universe.
The spoon that sits in front of me gives me no reason to act in any particular way, but happiness and suffering do.
And there’s no logical justification for believing that my own well-being matters more than the well-being of any other sentient being.
Certainly, from a public policy perspective, where this type of impartiality is more accepted, the goal should be to improve the general well-being of the population.