Ask Lemmygrad

Countries all over the world need to mantain trade surpluses (value $ of export more than import) in order to get dollars in order to pay debt or buy other commodities, like oil from saudi arabia (which explicitly only sells it on USD, aka the petrodollar).

Who produces the dollars? The US. So basically the US can mantains this insane trade deficit (value $ of import more than export) because they literally have the ability to print the international reserve currency and the currency does not super hyper inflation because of the high demand worldwide, any currency would collapse in a minute with a trade deficit like the US.

So the USD losing its global status would mean that the US can no longer import as much commodities as they do, theyd need to start producing much much more commodities to balance their international trade.

In order to produce more commodities, more productive blue collar workers will be needed instead of the non-productice finance white collar bs.

Caused by the end of dollar hegemony or caused by something else?

Yes, Dollar hegemony makes it viable for the US to import a much larger quantity of commodities than would be otherwise possible. The loss of imports would not just affect consumer goods, but also intermediate goods. The loss of dollar hegemony will cause a temporary slowdown in many of the productive industries that America does have.