Can I just put it out there, that in my personal experiences...
Darkvision is not, and should not, be a big deal, especially in a combat-pillar focused game.
- Your adventurers should almost never be exploring in complete darkness; it hampers your perception and having darkvision Does Not Help that. If you're in actual darkness and the character with darkvision is asking what they can see, and Perception check they make is being made at disadvantage anyway, because that's what dim light does - and if you're in darkness, your darkvision characters are operating in dim light, within their darkvision range - further than that, and they're just as screwed as everyone else. (This is the biggest misinterpretation I see - darkvision characters making camp in darkness, or searching in darkness, and doing so without penalty 'because they have darkvision' - no! That's not how it works.) Darkvision or not, you still want lights when you're exploring - darkvision is just a fall-back.
- If you're in dim light, and the darkvision character can see ass though in bright (within their range), that Does Not Affect Combat in any way. Fighting in Dim Light does not hinder you in combat at all.
- Darvision range is a hard line, and it's usually 60ft for most races - this is far shorter than most ranged weapons and many spells; if the enemy is attacking you from darkness 65 feet away, your darkvision is doing nothing whatsoever, and they'll have as much advantage on you as on someone with normie-vision.
