Pegged currencies are doomed to fail. GBP is efficient now that it is free from any ERM or gold constraint.
The list of currencies pegged to the USD is a long one as I recall. I’ve always been amused by the CCP insisting that the Yuan become an international reserve currency - while also insisting that the PBC maintain a substantial currency desk tasked with pegging the Yuan to the USD.
Really surprised that you're even arguing here when it seems that you're not very familiar with the subject material. If you did a cursory look at those pegged currencies you'd notice that they are dominated by commodity exporters where the commodity is primarily priced in USD. In China's case, they are much more flexible in how they manage their currency (not a hard peg), so I expect that the system will be more durable as it eventually weans off a peg. The flexibility in the peg reduces the volatility of the currency, but widening differentials between onshore and offshore Yuan should tell you how well the PBoC is doing. Another note on the Yuan-- arguably China does not need to manage the currency that much because most of the trade is in dollar terms. As long as China maintains its policy of buying US-denominated assets with dollars, the demand for Yuan is unlikely to spike up. This is why all that conspiracy-theory BS of China yanking treasuries does not make sense -- if they did that, the Yuan would appreciate dramatically, reducing China's competitiveness for a long time. The China-US relationship is more intertwined than most people realize.
This Dalio article posted by Nooby (see below) can be highly recommended to several here who seem to have an interest in MMT but not much understanding of it. This article states what I too have pointed out, which is that MMT is to some extent an explanation of what the U.S. Treasury and Central Bank, has been, and is doing with regard to managing monetary policy and accommodating fiscal policy. This is, needless to say, very different from what the general public supposes. And, sad to say, even some well known economists seem to have not quite kept up. So let me here quote from L. Randall Wray's 1998 Book, "Understanding Modern Money -- The Key to Full Employment and Price Stability." A scholarly work that I can not too highly recommend as a jumping off place for anyone seriously interested in the Money Theory. Chapter 3, starts by stating that the prevailing view is that ..."Monetary policy has to do, primarily, with control of the money supply, while fiscal policy has to do with government spending, taxing and borrowing. Wray goes on to explain that this prevailing, or conventional view, is "quite different from the Chartalists approach, which can be traced from Adam Smith through John Maynard Keynes." The "chartalist approach" lies at the core of Modern Money Theory. Fully understood, according to Wray, it "...would lead to a very different view of appropriate monetary and fiscal policy goals." For example, "deficits would be accepted as the 'norm.' And rather than trying to use monetary policy to achieve stable prices, monetary policy would recognize that its role is to establish the short term interest rate. ...Fiscal policy would be used to increase stability of the value of the currency." What I see as the most common correct but hopelessly misleading assertion coming from those who don't fully understand MMT is the claim that according to MMT, government can simply create as much money as it wants whenever it wants. Although technically correct, this is highly misleading, because no responsible government could manage its economy without reasonable constraints without creating an economic disaster. MMT does rather convincingly make the case "that there are really "no real constraints to prevent raising of the deficit until unemployment has been eliminated." However, "... beyond that point, real constraints intervene so that additional deficits will run up against the inflation barrier." In 1998 when Wray wrote the above remark it was, it seems , at least a partial, tacit acceptance of the Phillips Curve (questioned and heavily modified in recent times).. We now have good examples of apparent, partial breakdowns in this commonly accepted relationship between employment and inflation. To my way of thinking, an equally great constraint on deficits comes from real productivity growth, as deficits must ultimately be justified in terms of productivity or inflation is the expected result. Also, I believe, still another constraint could eventually arise, though it would not, according to MMT, directly constrain deficits. Namely the amount of aggregate bond servicing that can be absorbed by the economy without either constraining discretionary spending or resulting in unacceptable inflation. (Keep in mind, however, that the MMT economists do not believe that deficits should drive bond sales.) Bond servicing is non-discretionary, and unlike other non-discretionary spending such as entitlements, it is also non prepaid. Excessive bond servicing could swell reserve accounts at perhaps a very inopportune time.