Russia and China are factory nations. Their economy only exists due to selling their goods to other nations.
This only happens if they keep their currency very weak against the currencies of their trading partners.
To say that two factory nations are going to combine to displace the US dollar as a reserve currency is asinine.
This doesn't mean that I'm a US dollar fanboi. Our currency, just like the currencies of the world, is wicked - in that it is based on debt (US Treasuries in our case).
The US needs to have the Treasury issue our currency, and only issue it against labor that has been completed - think public works projects for instance, that could then be spent into the economy. There should never be backing by debt - since debt is a claim on the future labor of a society. We are currently slaves to our debt masters.
Many don’t seem to understand that if the dollar got weak, a good bit of that factory activity would return to the US. China DOES NOT want that to happen. They are already having fits over supply chains getting yanked.