I thought you were going to talk about the government of a certain country making an investment in Bitcoin to make the economy better because the economy of a country is not in the hands of its citizens, they might have some influence in it but they can't make it good or bad, it's all about how the government governs the state and how they manage things, especially finances so that they keep getting more money from what they have instead of losing it.
Also, since Bitcoin is an unpredictable asset when it comes to its price, you never know what's going to happen tomorrow. What if a government invests $5 Billion in Bitcoin and the price drops 50% within a month, that will be devastating for them and their economy. So I don't really find it to be a viable solution for that problem.
Investing in bitcoin should be long term, not monthly. Only in this case, btc brings income. At least within one
BTC-cycle, that is, approximately 4 years. This applies to both private investors, institutional investors, and entire countries.
Perhaps the high volatility of bitcoin and unpredictability (although btc is already quite predictable in the long term) makes countries wary of btc and not rush to invest. But if you act deliberately, for many years to come, and not for a month, as in your example, then this is not much more risky than investing in the economies of other countries (where there are not less risks, but even more).
A price drop of 50% will not have any negative effect on the country's economy, because no country will sell at such a discount, especially after investing in a month. I am sure that if some countries take such a step as buying bitcoin, then this financial asset will be
frozen (will not be sold) for several years, at least.