Both my parents went to graduate school. One of them loved the academic setting and went through with the postdoc and then found a tenure track job, the other decided it wasn't for them. I talked to them recently and the one still teaching said they would never choose that path if they were coming out of college now.
It can take 5-10 years to find a tenure track job now because professors don't retire. I've seen 90+ year olds walking around departments, and 70 year olds are common. All the low hanging fruit is gone, so projects and problems take longer and longer. Together, it means that whatever semblance of academic integrity and honor is gone. There's too much pressure to produce something big that you'll hide data or even steal it. Even collaborations don't mean you'll see your name on a paper. My partner got their research scooped by former collaborators!! And your recourse for blatant plagiarism? Nothing! No institution will fight for you because your career doesn't matter to them. There's a huge pool of postdocs they can pick from if you give up. Most of the professors still pretend that they can talk things out and share data, or blame you for not anticipating the issues.
The pay is secondary for most people who made it through grad school. They generally _want_ to do research. But when the pay is less for a more toxic environment, it's a no brainer. And somehow the professors are confused why no one wants to stay...