I've just published my event bus component for ESPHome to Github: GitHub - robertklep/esphome-eventbus: An event bus component for ESPHome · GitHub
It can be used to remove the need for tight coupling between different parts of a project. I've been using it in a large(-ish) project and it has made it much more manageable (it has replaced many scripts and direct references to other components/objects, which also made it much easier to include or exclude certain parts of the project depending on the target hardware).
It's really only useful for ESPHome projects that use packages.