Its Azure Hardware division that manages its first party silicon and its deployment has a huge hardware and electrical engineering presence. These fields don't have as many people in America in them, because Software has paid so much more for the last two decades, why would anyone go EE when they could go CS and make 2-3x more. In other countries, these degrees were paid similar so there is a larger pool to pull from then in America.
You can't train a software engineer overnight to be a silicon engineer