I disagree with the idea that we’re all mercenaries. It's simplistic, devoid of nuance and ultimately cheapens us. Yes, obviously most people work for money, but that doesn’t mean profit is the sole driver. For example, I know tradesman who consciously avoid over inflating quotes, often offering discounts to older or cash-strapped people out of moral decency. I also know public sector professionals, highly skilled individuals, who choose roles that pay a fraction of what they’d earn privately, precisely because they’re committed to giving back to society in some form.
To suggest that everyone is simply acting out of self-interest flattens the moral and relational dimensions of why people do what they do; and often is just an excuse of the super rich.