Let’s go along those lines, the gold angle.
https://www.statista.com/statistics/267998/countries-with-the-largest-gold-reserves/
Now do I 100% believe these stats? No way, the US reserves have been questioned since 1971. But let’s take it at face value..........China does have the largest FX reserves on the planet and for good reason, its been depressing its currency for decades and can continually do so for many more and has been buying more gold in the past decade. But.......if they decided that a gold standard were the way to go they would need to necessarily harbor an illiquid asset to prop up what would be a “restricted-access currency.” There, they would need to change the dynamic to investing from primarily in US Treasuries which they cannot afford to do given it’s the only place they can run to garner the size they need. The global gold market is capacity constrained, the US Treasury is like a crack factory run by evil Oompa Loompas.
Your thinking is not out of bounds. The Bear and Dragon have many reasons to undermine us. But just like close-mindedness the old Soviet system, the former is too reliant on crude to ever make the USD irrelevant the latter is too reliant on US trade (and in some cases imports) to ever invoke a wholesale move away from the hand that feeds.
From what I’ve seen, China and Russia both only very sporadically update their gold reserve statistics, and most people believe they lie about the true amounts. I’ve seen articles that compare gold trade statistics to show that China and Russia must be importing far more than they admit to.
Also, to have some kind of gold exchange standard, both would have to allow holders of Yuan/Rubles, at least governments anyway, to freely convert their Yuan or Ruble holdings into gold. I do not trust either to honor that. Heck, even Nixon had to abandon it a mere 25 years after the USA won WWII.
I freely admit I don’t know how it will work, but I also am quite certain both don’t like the global supremacy of the US Dollar, and will constantly seek to undermine it.