"While offline hardware wallets can theoretically be more secure, the associated expense and increased complexity limits their use cases, so Proton Wallet aims to be the most secure, always-accessible Bitcoin wallet."
https://proton.me/blog/proton-wallet-launch#:~:text=While%20offline%20hardware%20wallets%20can%20theoretically%20be%20more%20secure%2C%20the%20associated%20expense%20and%20increased%20complexity%20limits%20their%20use%20cases%2C%20so%20Proton%20Wallet%20aims%20to%20be%20the%20most%20secure%2C%20always%2Daccessible%20Bitcoin%20wallet.