Personally, I used to dismiss most of the discussions about the nature of the petrodollar, considering them worthless conspiracy theories, but truth be told, I can count at least nine sources (now including you) immediately who were telling the same about its decline.

And I'm a scientific man, so for me, it's a sufficiently large quantity of samples to believe it makes sense. And, well, it makes sense anyway.

As far as I'm concerned, if cryptocurrencies are the assets that replace the power of dollar (mean it as you will), I'd be much, much, much happier.

If yuan, or even worse, ruble are the ones that become major players in either oil trade or any other, worldwide-important product, that would bring the threat of economic power of similar scale the US used to have.

In layman's terms: the key would be handled from one bad hand to another. And most importantly: not without conflicts.

Having another war between superpowers and/or the rules of Russia of China over global economy would be equally bad for me - while cryptos aren't really ruled by any single entity.

On the other hand, if you could exchange oil for e.g. Bitcoin, that would take away the point of said cryptocurrency, so I don't know.

What is sure is that cryptos are alternative assets for the poor, wherever they are on the globe, whatever they are considered (shares? asset? fiat? all? none? depends on who you ask)