"Well adjusted people so not want that power over other people"

There are certainly well adjusted people that would like to fix things they feel are inefficiencies or issues in their government, especially when those issues are directly related to their areas of expertise. Thinking well adjusted people wouldn't want to be in a position of power is exactly how you ensure that only bad people end up with power.

Power seekers acquire power, not knowledge seekers. This is from Plato’s The Republic so about as old as it gets.

We've always had sociopaths and narcissists, and if you're looking to "capitalism" as the reason why they exist, you're in out-and-out category error territory, not-even-wrong territory. Now that this power exists to be had, human beings are racing to acquire it. If you think you can fix that by "fixing capitalism" you are completely wasting your efforts.

So if that’s not the answer, what is? Should we just throw our hands in the air and say that technology has defeated our monkey brains, and there’s no going back?

Given that these tendencies are not evenly distributed throughout the population, you can have structures that leverage the large mean to mitigate the worst tendencies of the extreme tails. Given that the natural state of things is that power begets more power, these are harder to build and maintain, but it can be done. In particular, Democracies and Republics are major historical examples of this.