I take your point Celeste...
Immigration in and of its self isn't the problem I think, but the numbers, when so large, create their own set of problems. Australia ships people off to prison camps on remote islands and leaves them there indefinitely, and Trump's America separates children from their parents as soon as they cross the border. I wouldn't have a clue what the answer is, but some of the solutions in place right now, make no sense to me.
I don't say this flippantly, but perhaps we're due another clear out...another war to end all wars, get rid of a few hundred million and make some room for the world's economy to grow. I live fairly close to an obvious target, and would welcome being taken out by a 'first strike' nuke rather than live in the brave new world that would follow.
With so many of us crowding the planet, the old order of one country one race has long since passed into history. The internet and mobile phones have given everyone the ability to see what they're missing. We humans...we just never know when to stop.
In the words of that old song...."They paved paradise, and put up a parking lot."