There are a lot of people who will pay considerably more money to get an extra 5% performance, particularly in the case of lenses. We all know that each additional increment of "sharp" costs more and more. Past a certain point it gets to realm of pixel-peeping differences. Where it does seem to make more real-life, discernible difference is with long lenses, as most of us are enlarging and cropping our (bird) images and hence exposing any shortcomings in the lenses more than with some other types of photography where the whole frame is routinely used.
When it comes to a camera body, it's tougher (for me, anyway). I have not bought a "flagship" Nikon camera since I got my Nikon F in 1968. I suppose one could consider the D850 as flagship level, but really, it's the D5 and D6 that are top of the line, and I never seriously have considered buying a camera in that series. The only reason I might possibly go mad and spend the big bucks for the Z9 is that it is going to be available well before the Z8 (or whatever the $2000 cheaper model will be called). I don't want to wait two or three years for a Nikon mirrorless camera with better autofocusing capabilities than my Z7. I don't need eye focus tracking kinds of features or a camera with a stacked sensor. But there is a part of me that does desire "the latest" and even "the best." Mea culpa. Actually by the time I get a Z9 (dreaming), it will have been close to four years since I bought my previous camera (Z7). A major upgrade every four years is not all that crazy.
When it comes to a camera body, it's tougher (for me, anyway). I have not bought a "flagship" Nikon camera since I got my Nikon F in 1968. I suppose one could consider the D850 as flagship level, but really, it's the D5 and D6 that are top of the line, and I never seriously have considered buying a camera in that series. The only reason I might possibly go mad and spend the big bucks for the Z9 is that it is going to be available well before the Z8 (or whatever the $2000 cheaper model will be called). I don't want to wait two or three years for a Nikon mirrorless camera with better autofocusing capabilities than my Z7. I don't need eye focus tracking kinds of features or a camera with a stacked sensor. But there is a part of me that does desire "the latest" and even "the best." Mea culpa. Actually by the time I get a Z9 (dreaming), it will have been close to four years since I bought my previous camera (Z7). A major upgrade every four years is not all that crazy.