Although I understand your point and would want to add that something like the Citizens United decision further diminishes power of the people without immense funds, I would like to point out, that participating in a democratic process doesn't merely mean drawing a cross onto a piece of paper every 2 or 4 years. Much more is possible and in fact necessary.
As an example and can be witnessed right now, there is a severe lack of organizing of pro democratic forces. Which is also the result of a decades-long campaign by the capital-interest-serving political establishment to delegitimize or outright destroy such movements and organizations, from worker's unions to independant media to the "Bernie Bros".
Make no mistake though. They did this, because they know, that this type of collective political actions bare real power. It is upon each one of us wanting to defend democracy, basic rights and the rule of law to do our part to take back that power. Voting is but a small part of that, if you don't have the people you need actually running, because they can't afford to and you cannot seriously pressure those elected like the donor-class does.
I'm sorry you feel that way and I find myself having the same thoughts from time to time. I have to concede though, that the US is in fact the center of modern Neoliberalism and legal bribery.
Yet... You know who the lobbyists and donors don't bother talking to? Bernie Sanders (and Ron Paul when he was still in office). Why? Because they know that they have core principles. Then the question becomes: How do we organize (meaning financial resources, outreach, strategy, know-how, recruitment, analysis, policy creation, media and many more) to get more of these people into office? And how can we put pressure on elected officials to enact "our" policies?
Agenda 2025, or the decades long judicial take-over did not come from Trump, but from such organizations like the Heritage Foundation. Which of course are funded by billionaires like Peter Thiel. These people and organizations have huge advantages over the rest, that is clear. But they need more than just money to be able to put public pressure on elected officials, to the point where 25% of voters are ride-or-die with that program and a further 25% are at least ok with it or were duped.
And yes, I am well aware it is an uphill fight. But please: Don't let bad experiences doom you to inaction. Especially when this very moment, with the daily over-reach of the republican regime, there is real potential to galvanize an effective resistance.