Population loss from now to 2050 will cause about 20-30% in economic damage or about a $60 trillion in economic loss. The GDP of a country is the amount of working people times the average economic contribution from each person. If your economy has 30% fewer people and all the people had on average the same productivity then you would lose 30% of your economy.

https://www.nextbigfuture.com/2023/05/low-population-in-2050-for-50-trillion-economic-loss-over-ten-times-more-than-climate-change.html