Apps are a method of bundling multiple dashboards and reports into a single object that can be published and shared within the organization. Hence, instead of sharing individual dashboards and reports or granting permissions to an entire workspace, apps allow the author to choose exactly what content to bundle and share. Hence, apps provide an effective means of organizing shared content and controlling access.
When Microsoft launched the new workspace experience, apps effectively replaced organizational content packs. Moving to this new model greatly simplified the authoring experience of bundling and sharing content.