Removing stickers, Memoji, or emojis from an iPhone entirely is not an option because these are integral parts of iOS. Emojis and stickers are embedded into the system as part of the keyboard and messaging features. Memoji, specifically, is a personal avatar feature tied to the user's iCloud account, and it's designed to be a fun and customizable addition to messages, FaceTime, and other iOS features.
While you can manage and remove specific stickers or Memoji stickers from apps like Messages, the core functionality that integrates these features into the iPhone cannot be disabled or removed completely from the system. If you prefer not to use them, you can simply avoid adding them in messages or use settings to limit their visibility, but they will remain part of iOS as they are considered built-in features for personalization and communication.