If you're getting a PhD with the intention of leaving for commercial work afterwards specifically because you want a high salary, then yes, the PhD program is p

If you're getting a PhD with the intention of leaving for commercial work afterwards specifically because you want a high salary, then yes, the PhD program is probably a waste of time. Case in point, all my friends stayed to get PhDs and I left to go to industry. By the time they graduated, my income was already a lot higher than their starting salaries. However, people with PhDs have a much easier time getting promos at commercial places. They get a built in assumption of high competency, especially if the PhD is from a highly regarded institution. But if your intention with a PhD is to become an academic, and you want to spend your time teaching or doing research, besides being necessary it's also very worthwhile. Or if you just really enjoy learning and don't care so much about salary when you're done, then it's extremely fulfilling.