[kivlad]

Bots are officially sanctioned as such and have an application ID in the developer console as well as a label in the client. Alternatively, nothing's stopping someone from taking a user account's authentication token and making the same calls, but that's against TOS (Discord calls them selfbots). The KYC they use won't protect against this kind of abuse.

[ohyeshedid]

Not to mention the possibility of a widely deployed moderation bot being used to attack the servers/channels they're running on, en masse.