Multisignature security, or “multisig,” offers a different set of security guarantees than single-signature (singlesig) solutions cannot.
It is imperative to understand what we mean by “wallet” before I lay my case for one type versus another. A multisig wallet is referred to as a “vault” in apps like Bitcoin Keeper and Blue Wallet, while some also refer to it as the “coordinator” or “coordinating software.” It is basically a wallet that can talk to multiple signing devices and coordinate between them for signing transactions (generally using the PSBT format). In comparison, a singlesig wallet talks to one signer only. The singlesig wallet is also often the signer, meaning the keys are hot.
The obvious advantages of having multiple signers are to reduce single points of failure and increase redundancy in your setup.