I suspect this depends a lot on the culture, which itself likely varies not only by country but the kind of hometown we're talking about. Where I grew up, a smaller blue-collar city, it was expected of people to move to another (bigger) city to study and work, and remaining in your home town was considered failing. The idea of somebody returning after college is even more incredulous, even though there were quite a few roles in the industry requiring university level education.

To extend the anecdote, I saw this similar sentiment in many people who had grown up where I moved to study. So what I viewed as success or moving up in the world, they considered failing. So it doesn't seem that rational to me, but it's certainly real.

And now finally, living in a different country (which of course makes me very non-failing according to my hometown's criteria), it's an entirely different story: I've never in my life have had as many colleagues who were born, raised, educated, and found employment within the same 50 kilometer radius. And they're all perfectly happy about it.

I have no big point to make here; your comment just stirred this realization into words. I guess I'm wanting to say that these thing vary a lot, and its hard to generalize.

There are not many people living in those smaller blue-collar cities.

I grew up in an exurb of a larger city, and most of those I grew up with live close enough to where they grew up that they meet in back in the home city every weekend to be with friends and family. The larger point is most people already live in a metropolitan area and remain in that area. It might be a different city within it, but still the same area.

I'll guess in your case while most kids did live the town you grew up with, most moved just a few hours away to a city. As opposed to many hours away to a city in a different state.