What do you mean what’s the catch?

Here’s the criteria that the score is build on.

From a quick glance, I’d say US is majorly lacking in:

• Equal opportunity to participate, vote: from felons bring denied voting rights to gerrymandering to Wisconsin votes being worth 4 times as much as California votes in presidential elections die to the EC, there’s a lot of fundamental issues here
• Independence of the judiciary: the supreme court is not independent, and presidential pardons are a mockery of any justice system

Looking at the list, less a catch more a difference of ethos. Higher taxes for better public services and more even wealth distribution for social cohesion.

Many are less diverse than the USA, which brings pros and cons too.

Do you mean “okay, but why is it still better to live on America than those places?” The answer to that one is, for the most part, it’s not. (I have lived a fairly sketchy life but the three times I’ve had guns drawn on me have all been in my brief visits to America.)

Do you mean, how are they more democratic? Gerrymandering, unlimited campaign contributions to “PAC” which are absolutely totally not working with parties and of course, the obscenely impressive ways pork gets stuffed into the most innocuous of bills by design all come leaping to mind.

In the US there are 2 political parties

In Denmark theres many more. The current government is 3 parties, and theres a total of 13 iirc, currently elected parties.

You can (most likely) find a political party to represent you.