I vaguely get the point here that user stories aren't enough, you need pictures too. Maybe the bigger problem working this way is that you end up wasting a lot

I vaguely get the point here that user stories aren't enough, you need pictures too. Maybe the bigger problem working this way is that you end up wasting a lot of time creating stories for the whole project, when you should use more of a just in time approach and only thoroughly define and then design those things that you are about to work on, with consideration of the eventual overall conceptual design in mind.