On what do you base that opinion? To hear the Chinese government you'd think Belt-and-Road is next to perfection in terms of infrastructure, while oppositional organizations tend to portray it as a relatively hastily rolled out, poorly constructed shambles. The truth is likely in between. And regardless, you still have to show how that might cleave petro from USD.
Definitions: There are two sources of demand for USD. One is the ability to purchase oil, and the other is organized international crime. I would consider crime a fair-weather investor, so the big demand for USD is really based on the ability to purchase oil.
First, examine the history of shipping tonnage [1]. Observe how quickly Chinese ports have come to dominate all world shipping. This is representative of the general trend of global supply chains coming under the centralized control of the Chinese government. Nothing presently happening in the US will improve our trade balance in the near term.
Second, examine the beneficiaries of belt-and-road [2]. All of these countries will have an incentive to have reserves of CNY. Some of these countries are significant oil exporters. If oil exporters start hoarding and regularly trading in CNY, then it's a small stretch for, at least some of them, to start trading oil for CNY.
Third, since oil is fungible, any nations trading oil for CNY will peg oil to the Yuan in addition to the Dollar.
Fourth, the governments of some nations, notably Iran, publicly believe that petro-dollars have motivated the government of the US to engage in warfare in and near their countries. They are furthermore publicly opposed to this, and publicly supportive of China ousting US hegemony.
Then, my argument. Belt-and-road gives a large number of nations a reason to hold and trade in CNY. It's a small stretch for some of those nations to start trading CNY for oil as well. Belt-and-road nations will have an expanded connection to the Chinese military, and success of belt-and-road is a face-saving issue for the Chinese government. That means efforts to oppose it could spark military tensions with the Chinese. This makes it plausible that wars to preserve petro-dollars are unlikely to succeed in belt-and-road nations.
There is almost no international demand for USD to acquire US produced goods or labor. This means USD is unlikely to succeed in an environment where it has to compete with CNY as a reserve currency for oil.
The US has a higher nominal export value of any country except China. Both economies are not highly dependent on exports, but their economies are so huge that they still dwarf the next highest countries on the list.
This is possible only because of the general demand for dollars. If the demand for trade with the US was based only on our goods and services, then we couldn't import as much as we do. If demand for dollars dried up, then our spending would be constrained and our quality of life would drop. So I think, anyway.
