The primary motivation of BIP-327 is to create a standard that allows users of different software projects to jointly control Taproot outputs.Potential benefits of MuSig2 include better privacy as well as fee reduction as the on-chain footprint of a MuSig2 Taproot output is essentially a single BIP340 public key, which is indistinguishable from regular, single-signer Taproot output even when they are actually controlled by multiple signers.
