Well, I agree that we should transition to other energy sources, but that's not really topical to the article. It doesn't matter much whether we use oil or not

Well, I agree that we should transition to other energy sources, but that's not really topical to the article. It doesn't matter much whether we use oil or not domestically. It's whether or not major chunks of international trade will remain denominated in dollars. Oil just happens to be a major, internationally traded commodity, and oil markets are mostly denominated in dollars because the dollar is seen as the most stable/reliable currency (as opposed to the domestic currencies of oil-producing countries say). The threat of oil-producing countries shifting their exchanges from dollar denomination to a non-dollar basket of currencies is that all of a sudden the demand for this vast amount of dollars in circulation outside of the United States will drop, and there's very little that the U.S. could do about that immediately. If the demand for dollars drops, its value relative to other currencies drops, and the United States will face massive inflation in imported manufactures, commodities, and raw materials. Producing green technology at home may wean our dependence on oil, but doesn't do much to prevent our currency from collapsing due to a sudden drop in demand for it abroad.