You don't care if Africa and Asia empty themselves and their social problems into where you live. I do - immigration of skilled workers that are urgently needed is great but having millions of unskilled immigrants would be a bad idea.
You do realize why Africa and parts of Asia has problems ? Because we bankrupted their economies. They used to be perfectly sustainable until our governments came down there to "improve things". It started with our plundering of their mines, destruction of their farming industry, and now is followed with the so-called "foreign AID" (an AID that disallows them to restart their farming business, we flood them with so much food that any farming business down there is doomed to fail, and farming is the basis of any economy).
Of course it would be painful to move out of this state our own governments created, but in the long run far better than continuing to abuse them.
"We" bankrupted their economies?
Unless you are a senior guy at the IMF, I assume you mean your grandparents helped colonise places. And I assume you are richer as a result of your ancestors' looting Africa and Asia.
My folks had nothing to do with it so less of the "we" please.