If the USA kept on a gold standard, Fr Knox would be even emptier than it is.
https://www.moneyandbanking.com/commentary/2016/12/14/why-a-gold-standard-is-a-very-bad-idea
There is no doubting that getting away from the gold standard has lessened the frequency and severity of recessions and it’s basic Econ 101 that eventually all your gold will be taken away. Fiat currency isn’t perfect, but material backing is far worse.
No, its made them worse. 1980s, Asian financial crisis, 2008 GFC - and what's coming in 2023 and 2024
And also - who's going to take away all your gold? Its economics 101 that if you "lose" your gold, you will have to devalue your currency to get it back.