Context is the bottleneck for coding agents now

There's a misunderstanding here broadly. Context could be infinite, but the real bottleneck is understanding intent late in a multi-step operation. A human can effectively discard or disregard prior information as the narrow window of focus moves to a new task, LLMs seem incredibly bad at this.

Having more context, but leaving open an inability to effectively focus on the latest task is the real problem.

No, I think context itself is still an issue.

Coding agents choke on our big C++ code-base pretty spectacularly if asked to reference large files.

Out of curiosity, how would you rate an LLM’s ability to deal with pointers in C++ code?

If you have lots of pointers, you're writing C, not C++.