Indeed, many of us can get paid more in industry. (Computational applied mathematician here.) But (i) professor pay isn't terrible in the grand scheme of things, and (ii) I view my salary as paying for the things I wouldn't want to do for free, e.g., grading exams, serving on committees, etc., and I'm reasonably well-compensated in having my own time to do the things I love enough to do for free: my own research, work with grad students, learning about things I find interesting and teaching a course on it, etc.

But getting here wasn't easy, took equal measures of hard work and luck.