Over 98% of cryptocurrency is stored securely offline and the rest is protected by industry-leading online security. Your account is also subject to the same scrupulous safety standards, including multi-stage verification and bank-level security. You can even lock the app with a passcode, or remotely disable your phone’s access to the app if it gets lost or stolen.
To understand the revolutionary impact of cryptocurrencies you need to consider both properties. Bitcoin as a permissionless, irreversible, and pseudonymous means of payment is an attack on the control of banks and governments over the monetary transactions of their citizens. You can‘t hinder someone to use Bitcoin, you can‘t prohibit someone to accept a payment, you can‘t undo a transaction.