Ordinary people should care. Just ask the Japanese what happened to their UST investment (relative to the Yen) after the Plaza Accord.
Traders hedge but not central banks. Central banks always carry long positions.
When you buy futures to hedge your bond transactions, there is a cost and although you are protected from the ups and downs of the bond price, you are still fully exposed to the currency market, inflation, and other risks.
Both forex rate and inflation have been consistently used by the U.S. to pay back its debt cheaply. This is the power of having the world's reserve currency.
The Fed was in the process of raising the interest rate when the pandemic hit. Now the Fed has very few monetary tools left.
There is a real risk/temptation for the U.S. to create a political crisis/instability somewhere to trigger a flight to safety (i.e. reason buy more UST). From this perspective, Trump was actually good for America. Relative to Euro and JGB markets, UST is still attractive.
