One proposal to buy bitcoin would use money from a revaluation of the country's gold reserves:
https://prospect.org/power/2024-11-26-crypto-plot-against-am...
Think of it this way - if there was no one to buy the gold from you, would you still buy the gold? Answer is yes. Many people all over the world would buy gold even if they could never resell it. The same can't be said about magic internet tokens. They have no inherent utility apart from the hope that a bigger fool will buy it from you at a higher price in future.
Why do you believe that?
Women store it in their teeth as a sign of strength, wealth, marriage, class, and a way to protect it. Generally not 100% gold, as that would be expensive, but it is some % of gold, and satisfies the belief. [0]
The interesting thing for me is that as the price of gold is driven up by wealthy countries, it increases the value for poor people that save in gold. The same thing is happening in bitcoin/crypto today.
[0] http://vietnam-phototours.com/blog/the-golden-teeth-of-the-e...