Suppose you're a billionaire (or at least have tens of millions). Where do you invest and keep your wealth? Regardless of where in the world you live or come from, your preference (for at least a portion of it) would be in a developed financial market, in a stable developed economy, with strong rule of law and without too much political meddling in property rights.
Depending on how you got your wealth (e.g. corruption), you may also have a requirement for anonymity: preference for Caribbean islands, Dubai, etc. But those economies are too small: they are highly dolarized and they are essentially proxies for indirectly owning assets in the west.
The main threat to USD supremacy is its application of sanctions. But even with those, and even if you're a Russian oligarch or Chinese corporate CEO with good party relations, your wealth is still likely safer in the west.
If global ownership of wealth and global financial markets are overwhelmingly US-based and dolarized (they are), then the dollar will be preferred currency for, debt denomination, long term contract denomination and plenty of trading and trade too.
For the renminbi to unseat the dollar, would require many changes. Not only dropping capital controls, developing deep and mature renminbi financial markets, providing renminbi denominated debt globally, etc (the sorts of things the CCP could do if it wanted to, though it apparently doesn't want to do). It would also require rule of law in China, and a global confidence that the CCP would not use China-located or renminbi-denominated assets for arbitrary leverage over countries, companies and individuals. The CCP can probably never provide that.
The euro still has more potential to gain prominence alongside the dollar, but that's apparently not the direction of travel (euro-denominated markets are too fragmented; legal systems are too fragmented and contract enforcement is a mess; financial markets are arguably less developed, certainly fragmented, smaller and less liquid and historic yields are lower; even if there was improvement on all of the above, demographic trajectories do not favour the euro area viz-a-viz the US).