Are Americans stupid? Why is there no future for science and technology without immigrating to America?

Generally speaking, Americans are not diligent enough, because this country is so rich that people can have a good living guarantee even without hard work.

Now there are many foreigners from all over the world in American universities, high-tech enterprises and Silicon Valley. These people are smart, hardworking and have dreams.

America is strong, not because Americans are awesome, but because they can attract talents from all over the world to use them. Moreover, the United States itself is a country established by immigrants. So some people say that if there is no immigration to the United States, science and technology will have no future.