to add to this excellent thread:
Democracy was *designed* to be bad from the start, and to fail people in exactly the ways it is failing them today and it has always failed them. Look at either the Magna Carta (last-ditch compromise to avoid another peasant + noble rebellion, retaining significant power with nobles by design) or the US constitution (Washington et al. didn't want those foolish poor people to actually have power since "they would surely make bad decisions" so they limited the vote to white male landowners).
From the very beginning the word "democracy" was a ruse, and the systems were designed to ensure that pay-to-play would let the rich have real control over policy. All of the forced concessions since then like women's suffrage or the Civil Rights Act have not touched that core structure, and even some of those are being eroded as we speak.
There are some very obvious design changes that would make "democracy" less broken in favor of the rich (although it would still be trash). Ask yourself why nobody is even proposing them. To give just one example: representatives could have votes in a governing chamber proportional to the number of voters who elected them, with each district sending the top 3 candidates to the chamber. Inherent issues with representative capture aside, this would indirectly re-enfranchise most of the ~40% of the population in many elections who vote for non-winning candidates. It would also massively blunt gerrymandering and get rid of the distortion that the Senate represents (100% also by design).
I don't know of any democracy in the world that implements anything close to this, and it's not even something that would require modern technologies. It's just something that would give the "demos" more actual "cracy" than the designers of these systems wanted to.
As OP is pointing out, the ways in which democracy actually ends up being "oligarchy with extra steps" are not accidents, flaws in the design, or unfortunate modern erosions of a historically-better system. They're the foundation on which these systems are built and the explicitly stated purpose of these systems. Developments like the Citizens United decision are just oligarchs haggling over exactly how much they need to spend to buy their power and/or how much effort they need to put in to pretend that's not what's happening.