The primary use case isn't just about shoving more code in context, although depending on the task, there is an irredicible minimum context needed for it to capture all the needed understanding. The 1M context model is a unique beast in terms of how you need to feed it, and its real power is being able to tackle long horizon tasks which require iterative exploration, in context learning, and resynthesis. Ie, some problems are breadth (go fix an api change in 100 files), other however require depth (go learn from trying 15 different ways to solve this problem). 1M Sonnet is unique in its capabilities for the latter in particular.