I think this would be a good thing, but if it were reality, I think many countries would encourage births before we got even close to net 0. This part we cannot really know.

Singapore is just one example that has been discouraging population increase then switching to encouraging population increase. https://en.wikipedia.org/wiki/Population_planning_in_Singapo... Yet there is still a net increase during all this time. https://www.macrotrends.net/countries/SGP/singapore/populati...

I think asking the world to agree on something this potentially controversial, when you and I can't even agree on the nature of the increase, is asking too much.