There’s also the carrying capacity of the area they’re emigrating to. Housing in particular is one aspect of it that’s already very very tight in most of the Western world. Even without immigration per se, this problem plays out every time a major company moves headquarters to a new city/state. Lots of new people, and a very slow to respond housing stock means surging prices. Schools and other social services also get stretched - but they’re much quicker to respond to the demand.