Many people who have been following me over the years are well aware the Petro Dollar was one of… if not the most important piece of the US dollar hegemony. The rest of the world has been forced to buy dollars to purchase oil. This in turn created an artificial demand for the greenback and is the central reason the dollar is the world reserve currency. The might of the US military and threats of violence is the other major factor. This is a cliff note version.
More and more other countries around the world view the US not as the city on the hill, but as the bully whose worn out their welcome. Since Washington DC has their tentacles on nearly every facet of the financial system, those who do not play by Washington's rules often find themselves cut off from the financial system and are forces to comply with Washington or else have their money stolen, cut off or held for ransom.
The US has gotten so full of themselves that they even threatened to kick China off the Swift system back in September 2017.