But that kind of agency is very, very weak; my vote has only a miniscule impact on who legislates. I personally would be quite willing to trade that tiny bit of agency for the government's agreement to not mess with so many things.
> Apropos of the system in the US, I think your politicians are far more partisan than those in Europe
I think this is true, and there are two reasons for it that I can see, one good and one bad.
The good reason is that there is more diversity of thought in the US in general, and that gets reflected in a wider range of political viewpoints. Some partisanship is based on honest differences of opinion in areas where nobody really knows the right answer; in such cases, it's better to have multiple viewpoints represented and give each of them a chance to try things out.
The bad reason is that more Americans have crazy beliefs, so that we have people in, say, the US Congress with widely different beliefs even about matters of simple fact like how old the Earth is. Of course that's going to make it harder to govern and increase the likelihood of highly polarized debates with no resolution.
I'm normally the first person to say that we should stop all the ill-informed people voting (which tends to mean excluding the majority of the right-wing), but this is so subjective that I don't even know if it's a real dilemma.
Ultimately any compromise will frustrate people, it's where we draw the line that counts.
Apropos of the system in the US, I think your politicians are far more partisan than those in Europe, although we have our own fair share of stupid policies based on popularism and ill-thought-through ideology.