This essentially ignores the condition of the US (and in particular the Bay area) as the tech capital of the world. The US is not bereft of talent, but the US alone does not produce enough tech talent to sustain its position in the world. In some cases, these American companies "that the H1B folks want to work" were founded by non-Americans or even better, were founded out of the US but moved there as a condition in an investment round.

You can be the tech center of the world. You can be an isolationist. You can't be both.