If you have 70-200E, or any G2 2.8 lens, you will realize immediately that your lens is outresolving Z6 sensor, what is not in case with Z7. Nothing wrong with that, as for me, but your opinion may vary. LZ
I have my D850 for high res shooting.
Currently I use my Fuji X100T for silent pic aquisition in churches, theatres or concerts
The 24MP Z6 should outperform the D5 in high ISO and surely outperforms her in silent shooting
the X100T will be outperformed for sure
most of my lenses outresolve the D850 at ISO 1800, not so much at ISO 64
My interest in the Z6 is
... small package
... highest ISO
... silent shooting
Even if I had a Zoom and not only top notch prime lenses I would not be tempted to use it on a Zx
I might be tempted to use the 1.4/105 at ISO 100k and f/1.4 in a theatre or church to show things difficult to show because of low light levels