If we always need more and more people in our country for the economy to be good, then at some point in the future, the economy and the country will fail. There's only so many people that can fit....
...before the ponzi scheme breaks.
It's already breaking.
Those who continue to foist immigration upon you are seeking to profit from it, that they may be able to continue to scramble to the top of the human heap, where they can at least glimpse some sky and breathe fresh air, while the vast majority squirm for position in the tangled pile below.