The most interesting question is why do Americans dominate software technology specifically? It is the most level playing field of all technologies. The skills to develop a state-of-the-art next-generation software technology are readily available and learnable globally while requiring negligible capital. On paper, you would expect this to be an area where Americans have the smallest advantage instead of one of the biggest.

Having worked with software engineering teams around the world over the years, and also done a lot of software tech M&A diligence, I've come to appreciate the massive impact that local culture has on being effective at advanced software development. This goes beyond the culture of the company itself; the level of ambition and optimistic self-belief required to be effective at developing very advanced software isn't terribly compatible with environments where Tall Poppy Syndrome/Law of Jante/etc is a real social dynamic, and that is very much the rule rather than the exception.