There is a very rational argument for the population being expanded: we need the population pressure to push us to invest in launch cost reduction, space mining

There is a very rational argument for the population being expanded: we need the population pressure to push us to invest in launch cost reduction, space mining and colonization so it becomes feasible to move heavy industry and eventually the population into space to leave earth to recover. I would rather see earth become a pristine zoo than a tomb and reducing population only cuts a small subset of the risks of becoming a tomb and exacerbates others.