Rhino 7 works with Silicon based Macs, but unfortunately the OpenGL drivers in the new Macs are not performing as well as the previous Intel based models. We are trying to work with Apple to have them fix bugs with their OpenGL drivers as well as making changes to Rhino 7 to work around issues as they come up.
If you are using Rhino 7, you do have access to the Rhino 8 WIP. For Rhino 8, we will be shipping a silicon based version of Rhino as well as use metal as a display technology.