IMHO bonds are in the same category of all the other worthless paper ( inc gold and silver) floating around the financial system they are worthless bits of IOUs
Many years ago there was a BIG Real Estate Company in Melbourne which borrowed from the banks a very large sum of money and the banks in their ultimate wisdom took the company shares as collateral
When the company failed naturally the shares were worthless.
Bits of paper have no value if they are backed by the company or country selling them
Bonds frighten me to death and they are going to kill the financial system of many countries before they fall out of favor