Why do you need at least one BTC and store it in a wallet where you control the private keys?
Because in this world:
Houses can be destroyed by natural disasters or uncontrollable factors, such as court seizures!
Cash stored in banks can be frozen by the bank, or the bank can go bankrupt, or the country can collapse and declare bankruptcy! Cash can become worthless!
Gold, silver, and precious metals are inconvenient to carry, and when the quantity increases, they become particularly heavy; they can also disappear if stored in a bank.
In essence, there is no absolute security for any asset in this world.
Satoshi Nakamoto's Bitcoin provides you with a perfect solution: as long as there is electricity and internet in the world, your Bitcoin will exist forever! No one and nothing can destroy it, unless you voluntarily give up your private key! This is the meaning of Bitcoin! Because of this meaning, a digital transformation is underway! Its name is blockchain, and its name is web3! The future has arrived!