The question keeps coming up, but the answer is still yes. With a compact camera now adding a 40mp image sensor the pixel count questions has escalated a bit, and I doubt they ever will stop.
It isn't about printing larger, otherwise I'd be more interested in pixel shift techniques than I have been.
My primary answer has been and will continue to be: particularly in digital capture, more sampling is better than less sampling, all else equal. While the gains would tend to be small and also somewhat dependent upon the lens, I'd expect the 40mp X100VI to produce slightly better information to work with than the 26mp X100V.
"Information to work with" are the operative words here. However, the more sampling you have of something, the more you'll have to have expertise in dealing with that extra data, and the more nuanced the difference you obtain will be. This is one reason why you see a lot of "I don't see it" responses. If all you want are out-of-camera JPEGs, the current 26mp X100 is fine (which is one of the reasons why I wrote elsewhere that Fujifilm really needed an X50 and X100 model, or perhaps X100/X200).
Other reasons exist for more pixels, as well:
- Cropping — You didn't quite have the right lens for your position, or you didn't quite get the horizon level when your image needed that so now you're having to rotate the capture. Having the flexibility to adjust the framing a bit requires more pixels. 40/45mp gives most people enough pixels left for their purposes even with a 1.4x or 1.5x crop. Moreover, that takes out lens issues at the corners.
- Aliasing — Aliasing visibility is reduced (for the same size output using all pixels, i.e. more dpi). I'd also say that post-Nyquist frequency "crud" visibility is reduced, as well.
- Lens Corrections — The image circle is nefarious. Center good, edge bad. Lens makers generally don't over extend the image circle (Nikon's Plena notwithstanding), because it's a cost in both size and money. Linear distortion correction requires more pixels to do well. But I'd also say that if we all treated our 45mp cameras as 36mp ones, we'd be complaining a lot less about things happening as we move to the boundaries of the image. Try it. Take something like the Nikon 28mm f/2.8 and crop it to 36mp on your Z7 II, Z8, or Z9. The lens looks a lot better now, doesn't it? (The more expensive S-line Nikkors, though, are pretty distinguished in how well they handle the outer areas of the frame, and the Plena takes that to another level.)
- Hiding Impacts — Simplistically put, most sharpening is changes in contrast at edges. Back when we didn't have a lot of pixels it was pretty common to be able to see the halos and shadowing that created on edges. When you only need 12mp at 300 dpi for your output (e.g. 8x10" print) and you have 45mp as your input, you can "hide" the defects of such manipulations, but still get much of the benefit.