I would wager the intention there is that the prefix is unnecessary or that it could otherwise reflect the name of the toolkit as opposed to the country. As an American I also find it a little "yeehaw, 'murica" and not the norm for design frameworks, but it's much ado about nothing.
Somewhere in London some intern at gov.uk is still not finished rewriting all the god-save-the-queen-hr-<color> CSS class names to god-save-the-king-...
haha, fair point. Still, I'm on the fence about how utility components are namespaced in USWDS. Perhaps giving users the flexibility to define the namespace might work better? One thing that bugs me is the absence of class-sorting like we have in TailwindCSS. Plus, there are some gaps I've noticed in USWDS. The naming, especially when comparing "padding-x-2" and "p-x-2", can be really annoying when switching around, maybe that could also be an option for the developer or project. Similar to the ideas antfu has on uno.css https://unocss.dev/ ♥