Control means responsibility
Self-custody means you (or your device) can authorize transfers. That removes exchange counterparty risk and introduces backup, phishing and device-compromise risk.
A seed phrase or recovery kit is not a password to reset. Anyone who copies it can move assets. Store it offline, never in screenshots, email or chat.
Hot, cold and vendor updates
Hot wallets stay connected and are convenient for smaller operational balances. Cold or hardware wallets keep keys off general-purpose computers, which reduces some malware paths but does not remove physical-loss or supply-chain questions.
Compare vendor documentation, firmware update process, supported assets and recovery design. Do not treat a wallet review as a guarantee that a device is free of defects.