What really worries me is that thinking about it probably the greatest positive influence you can have, at least in theory, would be to build something massivel

What really worries me is that thinking about it probably the greatest positive influence you can have, at least in theory, would be to build something massively exploitative and unethical, siphon gross amounts of money out of the economy with it, and then insure that money is not spent unethically again. A large part of why things are the way they are is because both wealth hoarders and consumers incentivize the status quo with their economic influence. Building systems, writing software, trying to raise awareness, etc does little to displace an economic system centered on exploiting weakness and maximizing profit. The most any one person can really, truly do is amass such a substantial portion wealth that they can dictate and control to be a force for good and not evil.