Earlier quoted context omitted.
The need to preserve culture goes out the window when there's no young person to change your bed pan.
Considering that Japan and Korea do just fine is proof that youre arguing with a straw man. Same with European nations that didn't just invite everyone and their grandma to immigrate such as Switzerland. The technological advances / robots will outpace the need for immigration, and has for the last decades too. Its just profitable for the capital as immigrants are a source of cheap labor which can be used to surpress…
Not sure about Japan, but anybody who thinks Korea is doing "just fine" has not been following Korean news. Daycares are closing left and right because there aren't enough kids. Now it's moving up to secondary schools. Soon it will be cafes and restaurants as there aren't enough customers. Then the whole economy will crumble down.
Technology doesn't help when there aren't enough people buying your product and services.