You're asking: what's the advantage of being willing to look farther afield to find your perfect job? That's what people in this thread are talking about when they say "labor mobility".

In case you want me to answer, there are myriad advantages: the chance to work with your most preferred tools, on a product that's more interesting you, with maximally compatible coworkers, etc. All the normal reasons people go somewhere besides where they were born for a job.