Digital BW, The Print

I'll confess, I'm a film die hard.

But I recently saw a very impressive print from a Canon 16 megapixel SLR.

It would have been maybe 1.2 x 40 cm.

Now, logic tells me film should be better.  I scan a B&W image at 4000
dpi - it resolves down to a level where the grain is just perceptible
as film grain using Tri X developed in Xtol.  That yields a 42MB file
with 16 bit grayscale.  And that's B&W so a colour file would be
around 120MB.

So, how can a 16 megapixel colour image (say 6MB grayscale image)
compete with a 42MB file?

Is this correct or am I missing something?

Cheers
Gareth