Ann: 2022 Annual Report, page-15

Come on indeed.
Which bank is going to be rescued next (whether US or international)? How many banks are solvent if they are forced to write down their bond holdings to market value?
Everything depends on market/investor/depositor confidence. No bank can withstand a determined run on withdrawals when confidence fades and of course as word spreads that becomes exponential.
Some black swan event that diminishes confidence internationally means that even marked down valuations cannot be realised as every holder sells to meet calls.
The recent bank failures have highlighted what can happen. The various authorities have drawn matters back from the brink but this a warning for sure.
Central banks can "save the day", as it were by massive injection of money, and other mechanisms that amount to the same, but the end result will be massive inflation and currency depreciation.
For gold mining stock investors, it will be which companies can survive a rabid tightening of liquidity by banks/institutions/investors/etc.
Physical gold has its merits in such times.