The problem is that Capitalism inevitably gets to the point where it is more detrimental to the population as a whole than it is beneficial

That's humanity, not capitalism. The Olmecs weren't capitalists. But, they formed a hierarchical society and there were some very rich people. "This highly productive environment encouraged a densely concentrated population, which in turn triggered the rise of an elite class.[14] The elite class created the demand for the production of the symbolic and sophisticated luxury artifacts that define Olmec culture." They grew and expanded until they caused "very serious environmental changes that rendered the region unsuited for large groups of farmers". After that, they died out and the region was sparsely populated for centuries.

https://en.wikipedia.org/wiki/Olmecs

It's not Capitalism that causes this, it's humanity. Also, no political/economic system is beneficial to the population as a whole. The whole purpose of political/economic systems is to allow the many to exploit the few. You can have an egalitarian society if you only have a few dozen individuals. More than that and you get hierarchies, and when you get hierarchies, the people at the top want to find efficient ways to make use of the people at the bottom. Capitalism is at least better than serfdom or slavery, both for the people at the top and the people at the bottom. The people at the bottom have a bit more freedom and a bit more agency. That makes revolutions and collapses less likely, which makes bigger hierarchies possible, which benefits the people at the top. But, it's not like feudalism, capitalism, or any other "ism" is designed for the benefit of the people at the bottom. The people who have the power to make the changes are the ones at the top, so they're only ever going to adopt systems that are beneficial to them.