We never really know what can happen with money. Looking at what happened in Vietnam like you mentioned, people who had huge savings in South Vietnamese Dong woke up to find it almost worthless after the government reset the currency. So yeah, holding assets like Bitcoin can be a strategic hedge because unlike fiat, it is decentralized, borderless, and not subject to government seizure or sudden devaluation. Now obviously no investment is entirely risk-free, diversifying into digital stores of value alongside traditional assets can help safeguard your wealth against extreme scenarios.
Fiat currencies in banks can be frozen, confiscated by governments and even you stored your fiat currencies at home, governments and central banks can do devaluation/ reset with terrible ratio like 100:1 or 1000:1, anything they want to make you poorer a lot.
With Bitcoin, you have your own bitcoin bank and governments can not freeze bitcoins in your non custodial wallets and can not devalue it.
If you dislike fiat currencies, don't choose Bitcoin because you think it is expensive, then you choose altcoins, it's bad too. With altcoins, governments can freeze your altcoins in your non custodial wallets. Altcoins are centralized and with smart contract as well as order from governments, your altcoins can be frozen anytime.
