The problem is in my experience (for quite some smart people) not "which job pays so much better (and thus facing a potential dilemma about selling out)", but rather about actually finding a job.

The job market does not like very smart people, but rather self-promoters and sycophant: I know quite some really smart people (with a focus on people having degrees in mathematics and physics (often comparable to PhD or post doctoral experience)) who had quite some difficulties actually finding a job in industry, and thus rather had to take the job positions that they could get.