Github actually has several hosting plans. Free plan Uber used is intended for open source projects of (potentially) wider public interest. Were the projects shared by Uber actually intended to be publicly used, or Uber just tried to save money and used the free plan for purely internal project?
Other (paid) github plans include totally private hosting, control-by-login hosting, when the project owner decides which github users get access. One example of control-by-login I know is an Unreal gaming engine, when Unreal charges developers $20/month for access, and also pays github for such setup.