when to add a cdn to your web app

hey everyone, im thinking about performance for a new project. were building a fairly media-heavy web app with lots of images and some video. right now, all assets are served directly from our cloud storage. its working fine for now, but im wondering when a content delivery network (cdn) really starts to make sense. is it purely about traffic volume, or are there other factors like geographic distribution of users or specific types of content that should trigger the move? what are your thoughts on the trade-offs between direct cloud storage and using a cdn in the early stages?