It's woefully naive to expect individuals to give that power up for social-positive goals, it practically never happened throughout human history. We achieve social-positive goals by behaving as a society and limiting what the powerful can do with their power - democracy, market regulation, progressive taxes, they are all forms of limiting the accumulation of capital and power.
And it just so happens that the current system we came up with - a mixed market with a strong, democratically elected public authority, yet freedom for individuals to pursue taxable profits - is the one that seems to work the best, because it pushes powerful people, both politicians and capitalists, to cater to the needs of society if they need to maintain their power. It's not an utopia, human nature has not changed and some would chain other people up tomorrow like in medieval times if they could get away with it, yet it works remarkably well.
It's nothing short of amazing that it works, really, we are privileged to live in a society where the powerful are so limited in what they can do with their power. We can still fine tune & tax more, of course.