Population collapse is not a real problem because more than half of us are doing bullshit make-work that doesn't need to even fucking exist except to support the two-winged bird of the MIC x The Poverty Industry. The benefits for a massive glut of old people are trivially paid for if you just don't do everything in the worst fucking way.
AFAICT we will not solve these problems, because doing so requires making things better. Instead we will mostly focus on ourselves all the way down the drain. But having 8 billion people doing a bunch of unnecessary bullshit in inefficient ways, which is very much the status quo that most of us can see trivially just by looking around or at most going outside and looking around, is fundamentally unsustainable. And I'm talking about the climate change here that you somehow haven't noticed I've been ranting about here voluminously since before you arrived.
Did your closing sentence sound clever while you were writing it?