Well the USD is one of the world's reserve currencies, not the only one, though of course it's the dominant one. A reserve currency is just a currency that central banks or other significant financial institutions hold "in reserve" for liquidity purposes and so on. Even if the USD was no longer the dominant one, which isn't necessarily great, it hasn't seemed to have been that big of a problem for the EU.
I also don't think there's an entire western hemisphere that is no longer interested in maintain "that". Despite online noise, and a few symbolic selling of treasuries, nothing has really changed. You have to remember that politicians, including EU politicians talk a different game to the public than they do when they're sitting in rooms together at Davos or wherever. There are other considerations. How good for the EU will it be if the US collapses into financial ruin (it won't)? Who is going to backstop their militaries against Russia or other bad actors? The EU can say well we're going to go sell all these treasuries, well they become worth less and less and collapse the global economy. All you hear about on the Internet is the US's dirty laundry. It's the same thing with China and their military and economy. Most people can't speak about their failures because they're not aware, we only talk about the United States (and EU and others of course) and those failures and we don't speak in terms of incentives and actions and reactions.
"China has hypersonic missiles the US Navy is doomed!" is often parroted - yet who can speak intelligently to what the United States has done to negate or address that concern? Very few. Why is that? Well we're all reading the same articles about China's capabilities - it's propaganda.
I also don't see the USD going anywhere, anytime soon since the US military enforces the petrodollar system. But sure let's talk about some Swedish pension fund selling $50bn (7% of Elon Musk's net worth - screw that guy) worth of treasuries and call that the death of the United States economy.
Please don't take this as a defense of objectively bone-headed things the United States is doing either, I'm just pointing out that it's much more complicated than what your comment seems to suggest.