Are we on the Edge of Collapse? Impressive Data from a Recalibration of Limits of Growth
(senecaeffect.substack.com)
id suggest if theres a population decline it's because some system has broken down
Modern population decline in the western world is because automation means people don't need 10 kids to do farm work so they can survive. The population decline is because the system is working so well we don't need as many people to survive.
As to an improveing living atandards for everyone, i also don't think that will occur, we allow the wealthy to accumate most increases now,
A decrease in the number of workers makes each worker more valuable. This has been seen in history after the Black Plague and more recently after the depopulation of Europe from WW2 of the most productive workers resulted in an economic boom.