If you redefine democracy to be the narrowest possible interpretation, you eliminate every government in the world. You also make the word pretty much useless.
There are some governments who claim authority to take any action authorized by the democratic process. The US government is not among them. Ergo, it is not properly classified as a "democracy."
https://www.youtube.com/watch?v=5tu32CCA_Ig
Every time there's an argument about wanting more democracy in the US, it seems someone always appears to say "but that's mob rule!". No, nobody wants mob rule. But there's a canyon between what exists now and what a more representative government could look like.
Predictably, the argument devolves into one about direct democracy vs. representative democracy, and that's really not the issue at all.
The issue is that the current system consistently acts contrary to the will of the people.
To quote the Princeton study from your video:
The preferences of the average American appear to have only a
minuscule, near-zero, statistically non-significant impact upon
public policy.That's a feature, not a bug.
There's plenty of time to undo the actions of the past 10, 20, even 30 years.
If you sit back on your heels, throw your arms up in the air, don't vote and say nothing, then you won't be participating in democracy. But if you do use your voice and vote then at least you can say you tried. Everything won't always go your way and we don't have a perfect system. But given our diverse population it is a pretty good one. I say that while in full agreement that there are a lot of laws that need to be reversed or undone.
You'll never entirely remove money from politics. And, we should keep trying to remove it even though we know we won't end up with a perfect solution. That said, lobbyists aren't inherently evil and many share our viewpoints (for example, the EFF)
The US is a plutocracy. It's in no sense a working democracy. There's a public voting circus every couple of years, but policy - which is the only thing that really matters in politics - is largely defined by Wall St, the Fed, and by mil-ind corporate lobbying groups.
All of the above are politically unaccountable and legally untouchable. See for example the ridiculous excuses made to prevent the passage of:
https://en.wikipedia.org/wiki/Federal_Reserve_Transparency_A...