From my perspective, the only reason they are resistant to societal factors that drive people to have less kids is that their strong religious values (which are

From my perspective, the only reason they are resistant to societal factors that drive people to have less kids is that their strong religious values (which are held together by their strong communities). So this really begs the question of what society will look like if the only people who will be breeding in the future are those who form tight communities that promote relatively religiously extreme values (that happen to include having lots of children).