I make more 100k per year contracting for a bank and I've never done a leetcode interview. I'm not in Europe though but I think I could actually make more there because my specialty is more in demand.
I suspect leetcode and whiteboard interviews are a way for Asians in the US to select for other Asians. Also more powerful HR departments leads to more "objective" and metrics-based hiring practices.
You are right about the corporate tax, but for regular employees Sweden is one of the worst places to be in terms of taxes. Roughly half of the cost to the employer has to be paid in taxes (first withholding tax, then income tax). And then VAT, gas tax, alcohol tax, etc etc.
I suspect leetcode and whiteboard interviews are a way for Asians in the US to select for other Asians. Also more powerful HR departments leads to more "objective" and metrics-based hiring practices.