Signatures are very much the hammer of cryptographic primitives. As well as authenticating a message, they also provide third-party verifiability and (part of) non-repudiation.

You don’t need to explicitly want anonymity or deniability to understand that these strong security properties can have damaging and unforeseen side-effects. Non-repudiation should never be the default in open systems.

This has come up a couple of times on the Fediverse as well as in the context of ATProto's permissioned data.