+1 to basically everything that has been said in this thread! I also use the NaturalVision Evolved visual mod, which already has a bit of a darker look/enhanced shadows, so it’s pitch black at night to the point where I can barely see anything. Adding on to what others have said, it would also be nice for city lights/street lights to have an actual realistic effect on how dark it is. Driving into Paleto, it shouldn’t be as dark as it currently is, as there is more lighting in this area. Same with Route 68. On the other hand, forests, low-lit/abandoned areas and such might be darker than the city areas, adding another layer of realism. Also, agreeing with others above, headlights and other light sources should definitely make surroundings brighter instead of doing nothing. As to the concern of people raising gamma to get past the darkness, this is valid, and does potentially pose as an advantage, especially during fights or pursuits.
The idea is great, just (IMO) needs some reworking, and if reworking/a different darkness mod isn’t possible or efficient, I believe it should be removed.
Here’s what it looks like at night for me... LOL