If someone doesn't like their current job, looking for a new one wont hurt them, they don't have to quit but they don't have to torture themselves being in a place they don't like.
For a lot of people, looking for a new job in the US these days is torture. It's hard, it's slow, it's wearying, there's no guarantee that you'll get even one response from dozens of applications, and in the meantime your morale and energy are sucked away working at a job that you can barely stand. And there are few enough jobs available (on a per-job-seeker basis) that jobs tend to be stingier on pay and benefits, let alone satisfaction, than in the past, meaning that there's less of a payoff for switching even if you manage to find a job you like more.
Does it occur to anyone that they're comparing euro salaries with dollar salaries (which is a 34% difference)?
In the article it looks like all the amounts have been converted to US dollars. The nominal number of currency units isn't that important because cost of living is based in the local currency. The exchange rate doesn't matter unless you are converting your paycheck from Euros to dollars and then paying your expenses in dollars, which only works if you are dealing with people that would accept dollars (and why would they, for basic commerce in the Euro zone?).
It's the same idea that a dollar is worth "more", in terms of how much it can buy, in rural Wyoming than in New York or LA. You'll get paid more for the same job in New York or LA versus Wyoming because things like rent and food are more expensive. The nominal wage doesn't tell you much about productivity in this case, unless you think that people in NY or LA are inherently more productive in some way than people in Wyoming.