Do you or do you not?
Yes, because you can set the Near clip distance to 0.01, which is better than VRChat’s Dynamic or Forced (0.001). Just make sure the camera is referenced in the VRCWorld descriptor.
why is it better?
The main camera near clip in new Unity scenes defaults to 0.3, which is far too big for VR use. If you get close to stuff it disappears in front of your face. VRChat Dynamic and Forced set it to 0.001, but that is too low and causes artifacts with distant objects and shadows. 0.01 is a better compromise between the two.
I just checked and my world has a main camera because the template had one
I think the main camera object holds information for what the scene background is, if it’s the Skybox or a solid color. Try clearing the camera with a transparent black ( zero for each of rgba)