When creating a multisig with Squads, you can designate your browser or hardware wallets as the keys that can open the vault. If you own multiple wallets/devices secured by separate private keys, (ie: Phantom, Solflare, Ledger), you can utilize these devices as the signing keys on the multisig. This way, if one of your wallets gets compromised, your crypto is still safe because your other wallets have not been compromised. If you are using a physical device that stores private keys such as a Ledger, you can also choose to store your devices in different physical locations to protect them from IRL robberies. This is an extra layer of security best for those who have crypto savings they plan on HODLing for an extended period of time.