The new arrivals will not become productive, nor will the offspring of their many litters. The productive people are being rapidly replaced by the ungrateful indolents. Where this is going is obvious. The high standard of living that Swedes enjoyed will go away and be replaced by the same standard of living as in somalia.
The only way out of that is to invade another country, sap its resources as a parasite, and bring that country down too. Only problem, is that there are fewer and fewer countries left that the bloodsuckers can latch onto and suck out its remaining strength until it dies.
That was the Soviet model of Economic Improvement. It ran out when the assets stolen from Eastern Europe after WWII ran out.