It sounds minor that it finds files for you, but if you try it out, you'll see that it's a giant leap in UX and the extra files help it generate better code because it has more examples from your codebase.
My own tool `gptme` lets the agent interactively read/collect context too (as does Anthropic in their latest minimal-harness submission to SWE-bench), it's nothing novel.
You should try Codebuff and see for yourself how it reads files! It's not simply a tool call. We put a lot of work into it.