Sweden is a democracy. The Netherlands is a democracy. The USA is not a democracy.
Here is a rather specific map of the world. It is a bit outdated, but it shows you A/ the nations that have voter equality in place and B/ that even then there is a diversity of political systems in the world.
Folks love to say they are a democracy.
Old East Germany called itself a democracy, because people could vote and choose from three different parties. They were all communist parties.
We call ourselves a democracy, because we can pick from the pre-selected candidates of two parties, plus the very few folks that made it on their own.
Following modern Germany would be the easiest way for us to become a democracy. Basically, they got our system but then modified it to become fair for all voters. It is a simple fix and it kills gerrymandering pronto.
Here is my latest article on Doughnut Politics. We have a pretty big hole in our voting system.