Discord's Terms of Service expressly forbid self-bots. A self-bot is a bot that runs on the same account as a user, as opposed to a separate bot account. While self-bots might seem useful, they have been used in the past to abuse Discord's API at a large scale, which could negatively impact Discord's service for everyone.
Self-bots can perform actions at a much higher frequency than a human user could, which can lead to API abuse. Additionally, self-bots can be used to automate actions in ways that give an unfair advantage or disrupt the community.
Violating Discord's Terms of Service, including the prohibition on self-bots, can lead to the offending account being permanently banned. Therefore, it's important to ensure that any Discord bot developer you hire is aware of these rules and committed to following them. As a bot developer or user, it's always important to familiarize oneself with and adhere to Discord's Terms of Service and guidelines.