In my opinion this is possible, but not very likely. It would mean the escalation of the currency war and be bad for international trade. It would likely mean negative impacts on all the big economies. You are right that many countries are against the dominate position of the US Dollar and would like to change that. The problem is that all the countries would need to agree on a new currency to settle all the international trade. Both China and Russia would probably only agree if their own currency becomes the new world currency to be used. As for the smaller countries like Iran, they would probably ask for some monetary benefits to be part in the new system. The US Dollar is losing power every year, but to completely replace it it seems to early. Maybe an independent crypto currency could be the solution and a compromise for all countries.
We have seen Europe getting together and building euro, and they are all using that right now so we could say that it is not impossible. If places like China and Russia get together and create a new currency, even if just those two, I am sure that they will convince some other nations as well, not a lot, not as powerful as USA or Europe, but at least it would be a good start. Just imagine only Russia and China using the same currency, that alone is scary though for Europe and definitely for the USA.
This is why it would be wiser move from them but they are too nationalistic to do something like that, both will want their own currency to be accepted by the other nation.
I think, the United States will no longer be able to exercise arbitrariness if Russia unites with other countries, including China, which are proven Anti-US.
In various cases, we have seen the dominant action of the United States.
- Buying Russian-made weapons could lead to sanctions
- US imposes sanctions on RAB
- Repeated sanctions on Russia
Seeing all this, it is clear that the United States is claiming all services.
But if its opponents unite and protest, especially if Russia forms an alliance with a commercially powerful country like China.
And if they stop accepting US dollars, then the United States will be in a state of disarray.
And yes, we've seen countries in Europe come together to form the eurozone and use the euro as a single currency.
So, it is hoped that Russia, China, and other Anti-US countries will come together to bring about a major change in the world.