The people who seek professorships aren't motivated by money, they're motivated by prestige and tenure. If they wanted money, they'd have gone directly into the private sector.
But: there just aren't enough professorships to support the amount of PhDs we mint every year.
This is causes people to go off and postdoc for years hoping somewhere will accept them. Through a combination of luck and skill, some get a job as a prof and go through the tenure gauntlet.
But for most, eventually they have to give up on their dream and do something else - except post-docs are underpaid, so they start off in a worse financial position than they otherwise would.
This has a domino effect, because those post-docs compete for jobs with fresh PhDs who never wanted to stay in academia anyway.
The effect is compounded by universities increasingly relying on adjuncts as a way to cut costs (adjunct professors are heavily exploited, and they take the abuse because they feel like they need to boost their resume to get a tenured position). So, there are even fewer tenure track positions to go around
The only way to fix it is to either reduce the number of PhDs awarded every year (not going to happen) or incentive an increase in the number of professorships at universities.
In a way, this explains why many international Ph.Ds go back to their home countries these days to join local universities. It is good for these countries.
