The problem with action-style photography and a completely silent camera is I can never be certain the shutter release actually was pushed .... For my studio work with focus stacking done under remote control, this is not a problem and in fact, will remove a potential source of vibration. OK, the latter not so much with the Z7, so that's the main reason I dropped the DSLRs and went mirrorless for this line of work. Still my Z cameras are set to silent mode when I do high-magnification stacks.
"Machine-gunning" photography never appealed to me before, and the arrival of Z9 will not change that sentiment for me.