Fuji X-H2 resolution?

Jared Willson wrote:

At best, upgrading from a 26 megapixel sensor to a 40 megapixel sensor will provide about a 25% increase in linear resolution. In practice, it might provide anywhere from a 0% increase to a 25% increase depending on things like diffraction, lens quality, focus accuracy, depth of field, subject motion blur, and camera motion blur. So, one should expect generally improved resolution, but don't expect a WOW factor unless you are making large prints or zooming in.

Assuming you are going to the DPReview sample gallery and looking at images at 100%, I suspect the issue is simply your expectations. As megapixel counts climb higher and higher, the perceived sharpness at 100% gets lower and lower. Nothing weird about that--looking at 100% views isn't a fair comparison. When you look at a 40 megapixel image at 100% you are effectively zoomed in quite a bit more than when you look at a 26 megapixel image at 100%. If you want to know if there is increased resolution, you need to compare at the same apparent size, not the same zoom level. Higher megapixel count camera will always look worse at 100% than lower megapixel count cameras. It's not the sensor--it's just that you have more magnification, so you see the effects of diffraction, motion blur, missed focus, etc. that much better.

The issue of comparing two different sensors at 100% is the enlargement ratio is different.  If there is a 25% larger linear resolution, then the 100% view will have a 25% higher enlargement ratio applied.  A true comparison would be the same physical size.