If you've played previous editions it can be frustrating having a dark and spooky dungeon in 5th edition as your players frequently remind you that they have darkvision. In previous iterations of D&D, darkvision was much rarer (in 3e only dwarves and half-orcs had it) and low-light vision was the more common one, which merely doubled the range of light sources. You might feel like you can't have dark places be interesting anymore, but there's an important caveat that you're missing.