My biggest issue with code navigation on Github is that there doesn't seem to be a way to traverse the file tree without navigating through each directory.

It makes getting an overall sense of the organization of the project a bit of a hurdle until you actually clone the repo and look through it (which is too much work if I'm just glancing at something quickly).

For both new-to-project and new-to-programming folks, I'd argue this is very important as it's a scaffolding mechanism for learning the new system.