Engineering salaries in Europe are held back compared to the US by market forces (notably lack of investment), not unions. Unions representing highly educated workers do not typically engage in collective bargaining on salary, but rather supply legal aid and continuing education. It’s useful to have an army of lawyers on your side when the MBAs in charge try to cheat you and take away that promised equity, just to take one example.

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.

Good one, moved from France to Hong Kong, can confirm. We all move to non-unionized countries to finally be free to make money. When we go back, ofc we're all like "oh yeah you're so right, protect your right to work 35 hours, the boss is evil anyway" :D