The app, designed to help users communicate with each other, will be undergoing a slight redesign in which Facebook will be removing and demoting certain features of it to help simplify the overall user experience. One of those changes is the removal of the Discover tab, while other features like Instant Games and Transportation have been removed from the chat composer’s utility tray. While chat bots are still part of Messenger, they have been hidden.
Facebook did not mention why exactly they were making the changes they are making, but it has been speculated that this could be done to help optimize the app and make it more simple and faster to use. After all, if an app is too bloated with too many features that aren’t essential to the experience and is not part of the core, it could potentially drive users away from it and look for something else.
That being said, Facebook’s WhatsApp is actually a pretty good example, where over the years, the app has continued to maintain its core functionality while adding new features that don’t detract from it.