Overpopulation is the biggest non issue of all time.
First, go watch this concise take down of the flawed thought processes.
Long term the earth is doomed, but that’s like saying that long term people will die. No @$%.
Over the course of billions of years, the sun will expand and eventually the earths water and oceans will burn away, life will cease, unless we leave and find another world.
But a billion years from now is not a particularly interesting time scale that I care about. I care about today and the future on the scale of hundreds and thousands of years. And there I am convinced we will be fine.
Remember. The earth is NOT a closed system, there is solar radiation/energy flowing into the earth, and we can harness that energy to do work and transform matter into forms that are more desirable to our lives. So cheer up neo malthusians.