No, it's pretty easy to tell on a big enough screen. What's impossible to distinguish in a double blind test is FLAC vs good lossy compression or high end reel-to-reel against high end digital.
So then does the argument come down to a question of bitrate? Can we push digital projections beyond the point of human visual discernment, like we have with audio?
Yes, but I don't see many 16K projectors around.
That is not how high the cinema ever gets. The focus plane never completely aligns, the backgrounds shift, the projector vibrates and its lenses have edge artifacts. The scanable 16k film would look way better in Oculus VR than reprojected.
I wouldn't use the optics of commercial VR headsets as any kind of quality benchmark.