“There’s no borders at all for IT engineers. They can find a job anywhere.” Uhm yeah, but they also have parents, siblings, girlfriends. Probably they might have some properties bought already. So as it may seem really advantageous to be in IT, one might not be able to move to another country just like that...
not all of them, but many engineers are willing to move if they don't have kids and can make it work
I moved out from my home country and in the place I live now people are nice, but I am never going to be one of them (so there are also not nice people, but it is easier to deal with not nice people from your own country).
Some people have it even worse, because I can go back to my own country and have my friends from school and family quite close by. There are people who are children of migrants that are still treated on the streets like they are not part of that society even though they grew up in that country. It gets even worse for them when they go to visit their parents country because they look familiar to people but when they speak they use English or broken local language which makes them foreign there as well. In the end they are not welcome in the place they grew up, they are not welcome in the place where they fit in by looks. They don't have a place in the entire world they can go and feel like home.