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.
That's just a naive utopian fantasy.
The 51% voters are just another self-interested power center that will favor themselves and extract resources from the 49%. Not to mention that the system can be corrupted at every point. For instance, you still need police and military to enforce the results of group decisions; and at any moment they can seize power and take control, unless they're placated with preferential treatment by the system - reinventing systemic hierarchy.
There is no system that is immune to human corruption. And all the high-minded belief in the human spirit, and the good-will of democracy, falls flat with even a cursory examination of previous attempts.
There does not seem to be an easy answer for which political system delivers the best benefits.
Direct democracy has defects that have been apparent for thousands of years. I believe Plato was one of the first to argue that democracy turned into mob rule.[0] It seems unlikely that this was entirely original. Similar ideas must have been current in Athens well before his time, since they had abundant experience with demagogues and other problems during the Peloponnesian War. I don't think Plato's solution (Philosopher Kings) was correct, but it's harder to argue against his framing.
It therefore seems like a question of which approach is less bad up front and whether it decays into something worse. Personally I would satisfied with a functioning republic in the US, which is where I live. What we have now is an oligarchy.
[0] https://en.wikipedia.org/wiki/Plato%27s_political_philosophy