Earlier quoted context omitted.
In normal countries, the role of unions is to ensure that your rights and livelihood are secured when your body or mind sustains damage from a work injury. It sounds like your idea about what unions are and do are deeply informed by abnormal circumstances.
Perhaps that's why I've met so many engineers from these normal countries in my own, abnormally wealthy one. In fact, they've told me so, in so many words.
In general it’s surprisingly difficult to compare salaries, because the US is a complete anomaly here. The tech bubble, stock inflation, real estate prices in SF and NY, student debt are all contributing factors.
In my anecdotal experience, there is little difference in actual disposable income for software engineers in the US and North West Europe, even when one makes $200,000/year and the other makes €100,000/year.