>Proportional representation definitely helps here.

With this logic doesn't the US have proportional representation as well? Didn't Trump win the popular vote and republicans the senate? The majority of voters won, end of story, and the ones who lost have another chance in 3 years to flip the board. Where exactly is the missing vent valve you were talking about?

>think that a lot of the issues relate to free flows of capital across the world, which leads businesses to be set up in areas of cheap labour, which makes people in developed countries angry and more likely to vote for anyone who'll promise to fix it

Well yeah that's the big issue, but nobody will win the elections by saying they are slaves of the capital class and doesn't matter who you vote for as they are powerless to change the crooked financial system that actually runs the world even if they win the elections since the finance systems globally connected and easily moves to the areas with most stability and tax benefits even if they are undemocratic.

No. The US has a first past the post system that naturally forms two parties which in turn fuels further polarization. A rep runs in a district and it's winner take all. In theory (totally unrealistic in practice) you could have a single party win all the seats by achieving 51% in each individual election. The other 49% of voters (ie approximately half of the country) wouldn't receive a single representative.

Proportional representation has advantages but comes with its own complexities. However there are also other voting systems (such as ranked) that offer different tradeoffs independent of proportional representation. There are a lot of options out there and pretty much all of them would be more functional than what we use in the US.

About the only thing our system has going for it is that someone with an IQ well below 100 can still fully understand and even help audit it. (Or at least that used to be the case before electronic voting machines started appearing.)