Are they on felony probation? I have moved a few times with little money for better opprotunities. It seems like most people are just psychologically conditioned to die near where they were born. Most people just think the hardship is worth it, which is very much a choice. It is literally cheaper to move to most of the USA than live another month in places like california or nyc.
This ignores a huge array of practical reasons why people stay where they are.
Family networks are probably the number one reason. Child/elder care, food/housing/etc. sharing and a lot more are all major factors that by definition do not show up in economic reports.
And that's before people's "psychological conditioning" (which some people refer to as "being part of a family") is considered.
I, too, have moved around a lot - across the US three times, overseas and back once, with smaller cross-state moves in between. And it has worked out for me. I am also not married, have no kids, am not very close to my family, have a high degree of risk tolerance and high attraction to novelty, and seem to need a smaller community of folks in my life than many others.
I'm also well aware that I am an abnormally-unattached person. Most people have significantly more difficulty uprooting and moving somewhere else. Writing that off as conditioning that interferes with economic concerns not only fails to recognize very real economic aspects that don't show up a bank account, but also fails to recognize that humans value things other than money.
