However, with so many options, the versatilities of the flagship pro ILCs are in a different league. This is true of the Z9 with its 45mp sensor ideal for a wide diversity of genres : eg macro and landscape vs active sports and wildlife.... all the different RAW (or jpg) and Exposure settings let alone Focus and frame rates etc. We're dealing with a D850 on steroids.
I agree fully with
@Griffym it is essential to learn to put the Shooting Banks to productive uses. They are unavoidable if you want to get the value out of a Nikon pro camera. AS noted already, one pertinent example is how Custom banks enable up to 4 different RSF setups on the Z9. It sounds like some owners of the D500 and D850 avoided doing so, and so be it. I cannot understand how one can switch across all the settings between BIF and Landscape, although this assumes these are optimally setup in each case.
Since upgrading to a D500 in 2016, i've found the quickest setup is via
MyMenu to change Photo and Custom banks : set as the top 2 items. I still have these items in
MyMenu on the Z9 (pressing Fn4), although it's quicker to get at these as the 2 icons on the right edge of the i-Menu. I've come to appreciate MyMenu is also the fastest way to tweak the C1 and C2 AF modes, and also Focus with LockOn (a3) - quicker than using i-Menu. I find MyMenu to be ideal to tweak any one of a diversity of Settings [20 in total] which otherwise hide buried deep in its Menu. I suggest it pays off to trawl the Z9 Menus from top to bottom: using the Add Items eg GPS, Sensor Shield, Focus-Stacking, Battery Info, RAW Recording.... and more.
So actually there's more to configure and optimize in the Z9 besides the Shooting (Photo+Custom) Banks! One has to invest the time in experimenting to tame not only the Shooting Banks for your styles of photography, but also the i-Menu and MyMenu. IME, compared to the prior generations of Nikon Pro/Prosumer ILCs, the expanded options in Custom controls, the maturation of the i-Menu in the D6 and especially the Z9 are major innovations in their right. In combination with Customized buttons, I find almost all changes are very quick on the fly, but
only with the camera is setup for its tasks.