Just going back on topic for a moment - sorry.
Prompted by an earlier post, I recalculated the resolving power of a 36 megapixel sensor. Taking the pixel size of a photo from a Sony a7r, and assuming that the sensor size was 36mmx24mm (this won't be true - not even film frames are necessarily the "stated" size), and assuming that the pixels had no space between them, then there were 204 pixels per mm in both directions. Before tearing into this, note that the assumptions are actually not quite true; but it gives a reasonable starting point.
Now on to the second half of the original comparison. Film resolution is normally quoted with caveats as to subject contrast. The resolution of Velvia 50 (according to Fuji's data) is 80-160 lines per mm depending on the contrast. Set this against the 204 lines per mm of the sensor, the digital wins. In 35mm size. Go up to 6x7, and we have rather more lines resolved (the sensor will be 204x36 in the long side (7344), the film (say) 120 x 69.5 (Mamiya RZ67, Mamiya's figure) in the long side (8340).
I'm fully aware that this is less than the whole story, and there's the massive practical problem of exploiting the film fully. And that there are massive assumptions as to what the lenses can resolve, how it impacts on the overall performance of the system, the effects of the Nyquist limit etc. But it is something to ponder.