This is a great point. There are many avenues where one can invest time+money to make a positive impact on the world, yet "doing a Ph.D" is unfairly held up on

This is a great point. There are many avenues where one can invest time+money to make a positive impact on the world, yet "doing a Ph.D" is unfairly held up on a pedestal, even though there is no hard science showing that grad school is a prudent way to attempt such an endeavor. Edit: adding examples of ways that are less sexy, yet way more likely to be measurably impactful (in a positive way) 1. Teach high school, 2. Volunteer at your local soup kitchen (do it for 2 years -- less than half the time you'd spend in classes for quals), 3. Mentor an undergrad for a decade, etc.