Religious and wealthy people will continue above replacement forever. Probably why these two strategies persist. Who is the poorest person you know? Are they religious and do they have many children? Who is the wealthiest and how many children do they have? Flattening this curve has been the world project of the Anglo-American establishment post WW2, with dubious results - unless replacing themselves and their own populations was the goal. The demographic winter largely of their own making, a case of idealism meeting unintended consequences which may go down as the biggest blunder in world history.