Your answer is somewhat typical for Americans: because in my experience, Americans tend to think that all American developments are caused by domestic factors - governance, taxes, billionaires, whatever. Insular thinking, as if the rest of the world did not matter. Left or right, this is a fairly frequent pattern in the US.

But in the meantime, over a billion people elsewhere got out of poverty and built relatively developed economies. The US is no longer an automatic Nr 1 on the world scene by this fact alone. How precisely do you want to keep a massive edge over a billion hardworking East Asians who now have a lot of capital and know-how at their disposal?

Neither Musk nor Lenin can solve this. The US is simply in a relative decline.