I have cats and a parrot, and parrots need
some light at night because they have very very poor dim-light vision and can fall and hurt themselves thrashing around in panic if something wakes them suddenly in the dark.
Because of this, I don't have a nightlight as such, but I leave the light on in either the kitchen or the toilet - all our internal doors have a glass panel above them and that lets enough light through to the bird room for the parrot, but not bright enough to prevent him sleeping (they are completely diurnal).
Having that light on at night doesn't affect the cats' routines in the slightest, and it makes it far less likely that I will tread on Sonic if I get up in the night! He's too dark to see even if there's moonlight coming in, and he does so love to get underfoot
ETA: As others have said, cats can see well enough outdoors with moonlight, but they can't see if it's totally dark - they can navigate quite well using the other senses though, so even if it is dark would still be able to smell where their food and litter box are, and remember the route there. I think a nightlight is a good idea though.