A clear outcome of Snowmass 2021 and now the US P5 report was the community support for R&D towards a future muon collider. In this talk we will discuss the general physics program that becomes available to the community during the construction and completion of the future collider. We will review not only the main challenges and advantages of such a collider compared to other possibilities, but also the projected reach of several specific models. Additionally, we consider the physics possibilities at the necessary demonstrator facilities along the way. For example, a beam dump would be an economical and effective way to increase the discovery potential of the collider complex in a complementary regime.