It is a side effect. You should see that young kids will not speak their local language, but they will be able to speak Mandarin and English so much better than

It is a side effect. You should see that young kids will not speak their local language, but they will be able to speak Mandarin and English so much better than their parents. It is more a natural selection. Why do you want to keep local dialects when no one is going to use it? It is like watching a village living in remote area, romantically we wish they stay that way forever, but they will change, modernize and find a better way for themselves.