Instead of... what? It's not like you can make 2x the salary easily by instead becoming something else. Salaries are pretty flat, if you want to make money you should invest in somethig or have your own company.
Also: I'm not sure it's' a good idea to pick jobs based on salaries. It's good to not worry about money at all (which almost no SWEs' need to). After that I'd recommend pursuing sommething one finds interesting.
Edit: I think there is a cultural difference in the US where one is expected to aggregate net worth/savings throughout one's career, for many reasons (ability to send kids to better schools, saving for rainy day e.g. sickness, ...). In a welfare state I don't have that priority. I wouldn't switch to a job paying 2x the money unless it's really a interesting job! Because there is almost nothing that 2x the money would do to my lifestyle, the future prospects or security of my family etc.