The idea of human beings as rational utility-maximizing particles with insatiable hedonic desires is very much the product of an ideological project to justify capitalism as “natural” and has virtually no relationship to how actual human beings live but a lot of people have genuinely internalized it.
Trying to derive “human nature” by observing people under capitalist modernity is like looking at a bored, depressed wolf obsessively pacing a circle in a tiny zoo enclosure and concluding that this is “wolf nature.”