One reason to want to upload the entire codebase is that it allows them to have the model inspect the codebase during "thinking" without going back to the client to do real tool calls.
It's not a really great reason, because what's the downside of going back to the client? But that's the best reason I can think of.
It's not a really great reason, because what's the downside of going back to the client? But that's the best reason I can think of.