Bonds have been a particularly poor investment this century, as have Treasuries. In the old days, they were useful in having a balanced portfolio - safe bonds, with a moderate return to preserve assets and generate cash flow, balanced by a mix of stocks for income and growth. And, if one was really rich, real estate for the third leg of the table.
With the communists in charge, no bond you could buy today has a chance of keeping up with inflation. And as you noted, selling them as interest rates climb will just lock in capital losses.
Nowadays, if you're really rich you buy politicians.