I haven't opened these two wallets in a long time and noticed some interesting changes... MetaMask can use Google/iCloud and other logins to initialize the wallet address, and the mnemonic file should have an encrypted backup in the corresponding cloud, with the password being the wallet unlock password. You can export the backup yourself. Base (Coinbase Wallet) uses Passkeys to initialize the wallet address. You need to ensure that the Passkeys backup exists in the following locations (see image 3). For example, if you're using an iPhone, it will be stored in the iCloud Keychain by default, and you can see it in the "Passwords App," which is then synced through iCloud backup. Both are based on the security and privacy barriers of major Web2 companies to protect the confidential information of Web3 wallets...😏 while also enhancing convenience. By the way, here's a friendly reminder: don't find backing up too troublesome. If these new techniques fail or something goes wrong, you'll be in a hurry...