To clarify a bit, there are specifically two things that I feel are lost with widely prevalent racial darkvision:
1. The ambiance of storytelling as a DM when the characters venture into some ancient, lost, deep dungeon that is pitch black. Sure we can still say that the characters only see in grays, or that they can only see 60' out. But that's still enough for them to be comfortable in a dark space. The slight mystery and horror of an ancient dungeon filled with who-knows-what that I want to bring to the story is impacted if they can see everything in grays. I want them to have to pierce the veil of darkness with the effort of pulling out a torch and lighting it as the cavern drips with moisture in the distance, or have the wizard perform an arcane ritual to lighten the space,
2. The utility of spells, tools, and items that can help them deal with the darkness is reduced or lost. How many times do your players worry about bringing torches with them? How often do wizards worry about learning light spells? How often do your characters hope to find goggles of night or a potion that allows them to see in the dark? With so much racial darkvision around everywhere, almost never.
To me, darkness is one of the hazards (and storytelling elements) of the dungeon. Prevalent racial darkvision almost makes it a nonissue.
I get what you're saying, and it's cool to have those moments of total darkness, where everything is pitch black and you literally can't see anything. But beyond those moments, where you pull out the torch, it's really not that different. And in the context of D&D, it's very reasonable to have liberal use of
darkness because for underdark dwelling creatures (like the drow that have it natively), that's the method for putting their enemies in the dark.
If your darkvision characters aren't using torches, lantern, and spells, then you aren't using the disadvantages of range and Perception enough. Underdark creatures almost always have better darkvision than surface dwellers. Which means that you are always a target for an ambush, and one that is not broken by an attack. Every attack against a surface dweller by an intelligent underdark race with superior darkvision should be ranged attacks from 90-100', and then constant retreating to stay that distance from their target. Their attacks are with advantage, and the PCs are not only with disadvantage, but also with the chance of missing if they aren't targeting the right location. The most effective way of countering this is a bullseye lantern. Any other light source available to the party (except dancing lights which can be used once they are attacked) doesn't have the range necessary.
How many people would be comfortable walking around at late twilight, where the range of your effective vision is about 60', whether it's in the wilderness or a city street with no lights? Now tell them that monsters are real. It's not a nonissue at all. The only thing you lack is a natural source of total darkness, and you have magical means to handle that.
My baseline for what the PCs notice is their passive Perception, and with a -5 across the board there, it's a big deal. Consider that beyond their 60' range that the DC for noticing anything goes up considerably, because they are dependent solely on sound then. And sound in a dark, underground passage is notoriously unreliable.
Sure, they aren't in total darkness before they light their torch, but it's still a vital tool. Resource management disappeared as soon as
continual light (now
continual flame) became available. Once the wizard performs their arcane ritual once, the darkness is forever banished, and more effectively than darkvision.
But the storytelling aspect of darkness isn't generally total darkness, dim light, or bright light. It's about what is beyond the range of your vision. And that's easy to play up whether it's 6" or 60'.
Depending on how restrictive you want to be, you can take a cue from earlier editions and rule that darkvision isn't effective when within the radius of a bright light. So your
continual flame allows you to see clearly for 20' and dim light for another 20' but that's the extent of it, regardless of whether a PC has darkvision or not. All you need is one human to require it.
Even in AD&D, the only race other than humans that didn't have darkvision (infravision at the time) were halflings. Stout halflings had it, and mixed-blood halflings had it to 30', but other halfling sub-races did not. So this isn't a new thing at all. More importantly, infravision could be more problematic (depending on how you decided it worked), since warm-blooded creatures were more visible in the dark.
Really, what altered the problems with darkvision was a change in the way races and classes worked. In AD&D days, the majority of PCs (and people) were assumed to be human. Not everybody played that way, of course, but it was considered the standard. Now it seems that most people want to play something other than human. But like I said, all you need is one human to mess up everybody else's darkvision.
