This has nothing to do with dedollarization imho but rather with circumventing sanctions. China has been refusing to use Swift over fear of Western sanctions. Now China and Russia might even use barter trades at larger scale by the end of this year.
Yes, but for the West it's just easier to block Swift than a decentralized network. But in principle I agree. That China and Russia haven't obviously found something better to arrange payments than barter and a blockchain is a clear sign imo that they are in big trouble.
Barter is not a unheard of way to conduct business, even between countries without sanctions. The SWIFT network itself has become a sort of barter system.
I'm guessing in this case, they both distrust each other's currency, so they might as well trade in Bitcoin as in any other currency they'd both trust more... if there was one.
Still, the USD losing that chunk of trade, weakens the USD, which the US might feel the need to strengthen with some "decisive action".