Most developers jump on the hype train and don't stop to think about ramifications or requirements or purpose. Having said that, monorepos have their use cases, and they help eliminate the need to have convoluted tool chains whose entire purpose is to ensure version compatibility between various components of the system... before you can even start making a line of change on the dev machine.. or some asinine docker abstraction that you must spin up... essentially, if everything is in one place (and not conceived by antisocial pranksters), you bet it's meant to be together. This makes it easier for any number of different life cycle teams to pick up a project and not waste time chasing down silly time wasting issues.