I don't think that's the case. For example, there are plenty of large, mutlinational companies opening offices in Poland and hiring hundreds or even thousands of devs there specifically because you can get competent people for a fraction of what they'd cost in the company's mother country. Also, of course it's important for them that Poland meets the sane baseline you'd expect from a civilized country, in terms of infrastructure, stability, rule of law etc. - but once these conditions are ok, I think it's mostly about the levels of pay. Most companies at the top levels are ruled by bean counters after all, and they're are always looking for ways to increase profit (and hence stock value) - and reducing wages is a great and easy fix for that.