You're right, but we've never devised any system that prevents this from happening. Every single organization leads to a concentration of wealth and power. And even those ideally conceived to have counterbalancing forces, eventually are corrupted and subverted. It seems to be the steady state of reality.
All of reality clumps no? Any grouping tends to attract more grouping, because the force that created the group increases as its groups more. Be it wealth, power, or sheer mass.
This feels like a rule of the universe, from plants and solar systems to wealth portfolios.
Only catastrophic events break it up.
Maybe wealth should be reset every time? There shouldn't be inheritence at all?
This will be the reality until we come up with a way to make good decisions using direct democracy, and make that decision-making process so fast and easy that it can be used for any kind of group decision.
Concentration of power stems from our inability to make good decisions as a group of equals. We have to choose someone to make decisions for the group because there is currently no other working way to make them. Current technology might enable us to find some form of true democracy, but I'm not sure if anyone is looking for it.