> What, per your reckoning, is the petrodollar hypothesis?

Petrodollar recycling [1] backed by U.S. military might. It was a way, in the 1970s and 80s, for us to secure our oil supplies by e.g. guaranteeing the security of the House of Saud.

The point was securing oil. The dollar benefits were a side effect. The dollar is ascendant because we're massive consumers.

> I see it as the world starting to become very unwilling to trade anything at all with the US

This has nothing to do with the petrodollar!

> moving to other currencies and finance systems for trade and economic transfer

Sure. Folks talk about this. It has nothing to do with Venezuela. (Again, oil is traded in multiple currencies and has been for at least two decades.)

[1] https://en.wikipedia.org/wiki/Petrodollar_recycling