A world without banks and relying solely on cryptocurrencies would have some great advantages.

1. Financial Inclusion: Cryptocurrencies could potentially provide financial services to the unbanked population worldwide.

2. Decentralization: Without centralized banks, financial power would be distributed among cryptocurrency users. This decentralization could prevent monopolies and increase transparency and fairness in financial transactions.

3. Reduced Fees and Faster Transactions: Cryptocurrencies could offer lower transaction fees and faster cross-border transfers compared to traditional banking systems.

4. Security and Privacy: Blockchain technology underlying cryptocurrencies provides enhanced security measures and privacy features. Users would have control over their personal information and transactions, reducing the risk of fraud and identity theft.