Capital is just another name for power and powerful people fight to maintain and accumulate more power - welcome to the world, summer child. 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…
In every other attempt at forming different societies (from feudalism to capitalism) it's generally the ones good at power games that win, not the ones with the actual best abilites.
It is said of Stalin he was the best power game player ever born, he was equalled by no one in power accumulation games.
The possible exception to this is small tribes, where it was usually the people who added the most to a tribe that got power (if you were a power game player two friends could basically topple you).
But we're not going back to tribal life, so there we go. Capitalism is still the best of all the bad systems we have.