The good low light performance was amazing for its time (10 years ago), and it still holds up decently today. But let's not kid ourselves -- it has been clearly surpassed by modern backside illuminated CMOS sensors like the one on the Z9.

EDIT: sorry, it seems I'm wrong. I just checked https://www.photonstophotos.net/Charts/PDR.htm and while the Z9 has the clear edge with 2 more stops of dynamic range at low ISO, the D5 actually pulls ahead at high ISO. Perhaps the technological improvements haven't been that much for the shot-noise dominated regime.