How exactly does Solid decouple data and applications?

Would it not be easier for an app - like a social web page - to just store links to your data (profile, comments…) than the data itself? And is this not the whole point of Solid? I’m a newbie to Solid myself, and trying to figure out how a social platform would work with pods. My understanding so far is that instead of storing data, you’d just store references. Thus, when looking at a profile, or a conversation, the app would have to pull all the data from pods using the links provided by each user, basically re-generating content on the fly. And this would (at least considering storage space) be easier for the app or platform in question, albeit maybe providing a somewhat slower experience for the users. Right?