'Wait! Not in those shithole countries!'
Declining birthrates alarmists are essentially sponsoring the great replacement theory. Not with words or by shilling the conspiracy online but with their alarmism as conflated to just particular geographic areas without looking at the whole globe. Global population is still growing and will continue to do so during our lifetime.
The relative distribution of cultures , language, accents, religions... will change but that has always happened. It's crazy to just focus on a particular region. It's as crazy as saying: let's sacrifice present day Swedes and Norwegians to bring back the ancient Romans and Greeks .