Immigration and innovation

Is immigration to the US is required for innovation?
Ridiculous on it’s face. Did the Wright brothers invent the airplane? The times make the person, the person does NOT make the times!

If the US closed the borders entirely, would R&D, innovation, invention, come to a screeching halt?
330,000,000 Americans are incapable?

The smartphone would not have evolved if Steve Jobs’ father had not moved to the US?

Is immigration to the US required to compensate for a low birth-rate?
Is the so-called low birth rate in the US a so-called “crisis”?
If so, is immigration the cure or the cause? Many people don’t have children because they can’t afford to.