In D&D, humans, halflings and dragonborn are the only characters which lack darkvision.
Humans and halflings would otherwise make excellent rogues, but their inability to see in the dark is an enormous penalty in a game where monsters which detect the party can get the drop on them.
The ubiquity of darkvision 60 feet is also funny from a worldbuilding perspective. It’s SO common! Darkvision has its drawbacks, like not allowing color sight, but that’s relatively minor. Why does anything get lit, especially in battleground conditions?
Related topic: the trifecta drow, duergar and svirfneblin are more interesting than their aboveground cousins elf, dwarf and gnome. The undertypes deserve their darkvision; in their cavelike homes I see how it shapes their culture and is necessary, and they have dark-adjusted instead of light-adjusted eyes. But the overland types shouldn’t get to see in the dark just because their undertypes can!
If we still had low light vision (“Treat dim light as bright light”, as darkvision does, but without darkvision’s ability to treat no light as dim light), that might make sense as an adjustment for the aboveground types. In fact, this is very nearly the adjustment the game already makes: there’s two kinds of pitch black, the natural type and the magical type. If I simply adjusted things so that the Devil’s Sight trait means you can treat darkness as bright light (losing that distinction between mundane and magical darkness), and the Darkvision trait means you can treat dim light as bright light, then I’d be basically done.
This change works great for scouts, who can treat the dim light at the edges of the party lanterns as bright light (out to the edge of their own darkvision radius), and great for my physics engine sense of fair play (the only beings who can see in pitch black with no further rules changes are explicitly supernatural, though I think I’d probably extend the devil’s sight trait quite a bit; fiends, aberrations, and elementals with darkvision generally get devil’s sight; fey, beasts, humanoids, monstrosities and so forth generally do not). This weakens the darkness spell, since additional types of monsters would now have the ability to ignore it, but I tend to think of darkness as a weaker fog cloud anyway, so I’m hard pressed to care.
Oh, and of course Tieflings have Devil’s Sight (instead of darkvision). I’m torn about drow, duergar, and svirfneblin; I’m inclined towards letting them in the club too. The spell Darkvision grants Devil’s Sight as well, though Goggles of Night which give that additional property are probably one step rarer.
I especially like the way this puts everyone (except the underbeings and recipients of Darkvision) on the same level; those who can see in the dark will learn more details about the giant statue, but if one can see it, all can see it. Except for drow and tieflings. That’s fine.