Why do we continually need more people? It can't go on forever. More people means more emissions, pollution, strain on services, overcrowding and impact on the planet. Why can't we adapt to a lower birth rate and adjust our economic expectations downward to help that?Ultimately, we're teetering on a birth rate problem, accelerated by Brexit (1st gen immigrants tend to have more kids, younger), and insecure housing situations, or financial pressures of housing, are a major drag on people starting families.
It's a problem that needs tackling, and soon. A forward-looking government would do something. Will a government appointed by the elderly?
Continually wanting more people (whether that is by natural birth or importing people) is simply expecting your own kids to deal with an even greater problem tomorrow. It's not fair to expect them to do that.