I got handed an Ayn Rand sandwich,
Straight from a can, it tasted so bland,
I asked the lass to pass me a glass,
of Engels' Conditons of the Working Class....
I think that as long as people's individualism does not override the freedoms of others, then the pursuit of self-interest frees the mind to explore all kinds of avenues of spiritual discovery.
That's a big ask though, and most people have different ideas of what is fair when expressing their individuality, so I do think that there needs to be a mediator of sorts to balance the more extreme aspects of our self-interest, and make sure that no one is fully happy but that we're all kinda happy, in order for us all to progress, even if it's at a snail's pace.