I don't agree that more detail with more pixels is never mentioned. I think it is repeated all the time. In fact it is the prime selling point of more pixels. I think this article made the point that the eye cannot distinguish those fine details at normal viewing distances, and unless you are doing photomicroscopy those extra details will be lost at normal viewing distance. The need for antialiasing filtration can be eliminated at the sensor level as Fuji has already done. This also reduces moire effect.

I have to keep bringing this up: Diffraction is a function only of pixel size (smaller for higher density) and aperture, it has nothing to do with the physical size of the sensor. Does not matter if it is 17x23mm, 24x36mm, or 6x7cm. If you stop down for more DoF (or any reason for stopping down) the image gets fuzzier as the circles of confusion get larger. Canon and Nikon and who ever can not change the laws of physics (quantum mechanics). Cropping due to not using all the sensor is a bad choice in any case but to salvage an image. Use the correct lens and distances. Many people seem to need to actually try it, making large prints to see the diffraction limit effect on pixels (size) and stops. There is plenty of info on the WEB about it.

I don't remember where I picked this up, it is not mine, but thought it would make a good topic for discussion.

The megapixel myth
OK, so the sensor’s good, but there are only 16MP. This was probably the one thing that put me off most at first. As I mentioned, I started out with an 8MP 20D, then upgraded to a 12MP 5D, then a 21MP 5D Mark II, then a 24MP Sony A99, and each time I considered it an improvement. And it was – the sensor in each camera was better than the previous model – but how much of this could be attributed to the increase in megapixels and how many megapixels do you actually need? If you’re shooting high end fashion, or architectural work that will be blown up to the size of a house and then inspected with a magnifying glass, then you need a fair amount, but how many do the rest of us typically need?

The human eye can only resolve a finite amount of detail (see this link for a detailed explanation). At best this is somewhere around 200 points or dots per inch (DPI) so if you have an image from an X-T1 that produces images that are 4896 pixels by 3264 you can create a 24.5″ print. At this size of print, even if we add more megapixels we’re physically incapable of perceiving the extra detail.
When we create a larger print wouldn’t more megapixels be an advantage? For example, with a file from a D800 (7360 pixels by 4912) you can create a print that’s almost 37″ wide at 200 DPI. On the face of it then, more megapixels equals higher quality large prints, but this doesn’t take viewing distance into account.

Viewing distance is normally taken to be 1.5 the diagonal size of an image, so a 6″ x 4″ print would be viewed at about 11″, a 37″ x 24″ print at 66″. Because the 37″ print is further away the maximum DPI we can perceive at this range is somewhere around 50: we can’t make out the finer detail because our eyes can’t resolve that level of detail at that distance. Admittedly, you can stick your nose to the print, at which point you may be able to tell the difference between a 200 DPI print from a D800 or a 132 DPI one from an X-T1, but a) these differences will be small, and b) at normal viewing distances the differences between the two won’t be apparent.

Put another way, if you take viewing distance into account anything that shoots at 12MP or above will produce an image with sufficient detail for a high quality print, from a 6″ x 4″ postcard to a billboard across the street.

I have to keep bringing this up: Diffraction is a function only of pixel size (smaller for higher density) and aperture, it has nothing to do with the physical size of the sensor. Does not matter if it is 17x23mm, 24x36mm, or 6x7cm. If you stop down for more DoF (or any reason for stopping down) the image gets fuzzier as the circles of confusion get larger. Canon and Nikon and who ever can not change the laws of physics (quantum mechanics). Cropping due to not using all the sensor is a bad choice in any case but to salvage an image. Use the correct lens and distances. Many people seem to need to actually try it, making large prints to see the diffraction limit effect on pixels (size) and stops. There is plenty of info on the WEB about it.