Senate representation is one thing. Requiring a supermajority to pass anything in an already unrepresentative house is just ridiculous, and absolutely does diminish the quality of "democracy" the US has. Especially considering the US house isn't particularly representative either, due to a combination of an absurdly low representative cap and gerrymandering.
The US is certainly more democratic than it was at its founding, when neither the president nor the Senate were entirely directly elected at all, but it's not even close to as democratic as most Americans appear to believe it is.
I assume you're just talking about the filibuster. What about the other super majority votes like ratifying treaties? Also, they could use budget reconciliation to pass a few things to bypass the filibuster.
I think many Americans have been calling it a democracy for shorthand and people forget that it's an adjective for "republic".
Imo, "it's not a democracy it's a republic" is a pretty empty statement, because there are no pure democracies (and they are likely to be completely impractical anyways). It seems to be a weird meme among Americans that hints at some kind of exceptionalism, but has very little in the way of practical implications.
For the most part, everyone in the world means approximately the same thing an American does when they say democracy ("a representative constitutional democracy, probably with some degree of regional federalism and bicameralism"). The US neither resembles a pure democracy or the republic the founders created at this point anyways, so it doesn't really matter. These terms are pretty fluid.
Pure democracy is basically never the goal anyways. It's not a bad thing for a system of government to be not entirely democratic, there do have to be checks on pure majoritarianism somehow, but the particulars of the US' democratic lacks seem to be both worse than most Americans imagine them to be, and also far more vestigial if not accidental than they ought to be (many were really there to help uphold slavery and/or prevent reconstruction from fully succeeding).
At this point, the net effect of the US' democratic failings is to create a tyranny of the minority, which can hardly be considered a better failure mode than a tyranny of the majority.
"At this point, the net effect of the US' democratic failings is to create a tyranny of the minority, which can hardly be considered a better failure mode than a tyranny of the majority."
Any source fir it only being tyranny of the minority? I see examples of tyranny of the majority too.
Tyranny of majority is an apt summation of the problems facing Nom white peoples but is not accurate when applied to religious groups seeking to impose their regressive theological practices on everyone else. That is in fact fascist and unconstitutional. Weaseling around these intents is a tired tactic of the radical right that they’ve been using for decades to sway the opinion of their poorly educated constituencies.
The US is certainly more democratic than it was at its founding, when neither the president nor the Senate were entirely directly elected at all, but it's not even close to as democratic as most Americans appear to believe it is.