It's enough when it pushes the diffraction limits of normal fStops.
I can always down-sample, and indeed what I would like to see is in-camera binning. Astro cameras do that all the time, electronically combine 4 pixels for better noise and lower resolution, but you can switch to full resolution when desirable.
Imagine a 128mpx camera that with switch throw varies from very low noise and about 16mpx for interior action, in steps up to diffraction limited at about F4 for landscapes. No more complaints about huge files as they get downsampled before they become NEF's.