As you can see in my above post I did not︅ mention any cryptocurrency in this context.
To be a store of value the asset should︆ develop inline with inflation, with very low volatility. Under normal circumstances that should be achievable︇ with bonds but global central banks have destroyed this options (-> and pushed millions of︈ retirees into poverty).
Unfortunately, gold does not live up to its promise when it comes︉ to volatilty: In the past ten years alone gold first saw a rise to the︊ moon, just to collapse by 50%, and now being up half-way to its former high︋ it first reached about ten years ago. Not to speak of the catastrophic performance of︌ gold during the 1980's and 1990's. That alone makes it a rather risky investment and︍ not exactly a store of value.
You are absolutely correct that there are central banks︎ who continue purchasing gold and hoarding it in large quantities: Kazakhstan, Russia, Kyrgyzstan, Turkey, Qatar,️ China, Poland, Hungary .... . It should be obvious that this is much more politically motivated than anything else.
John Pierpont Morgan testified before Congress in 1912. That was 110 years ago. Back then gold was indeed real money and he could not have said anything else. The Dollar was pegged to gold (or vice versa, however you want to read it) and that's what was called the Gold Standard. Back then the Dollar was a young currency, the Federal Reserve -as we know it today- not even founded. Moreover, gold was still the dominant "currency" throughout the world - banknotes (printed money) had just︀ been invented.
Having said that, I am sure you admit that citing J.P. Morgan in︁ the context of our search for a "store of value" is not suitable anymore. Times︂ have changed too much in the past 110 years.