That is just the observers being impatient and failing to understand evolution or exponential growth. The USA is on a path to become Amish. They have 85% to 90

That is just the observers being impatient and failing to understand evolution or exponential growth. The USA is on a path to become Amish. They have 85% to 90% retention and about 8 kids per woman. Exponential growth clobbers any sort of linear change. The subpopulation with the highest growth rate will quickly displace all others, and then that growth rate becomes universal. Japan is not an exception. Japan is temporarily in decline. Look carefully though, and you will identify subpopulations in Japan that have high population growth. Some might only have a thousand people today, but with exponential growth they win in the end.