You just can not see in the dark. Well, unless you are playing D&D 5E as one of the something like 70% of races that have Darkvision.
Darkvision is pervasive in D&D 5E. Most of the playable races have it, almost all of the monsters have it. Tasha's even introduced an option to let everyone have it. It is just pervasive.
I've seen many adventuring groups with one poor human being lead around in the dark by his group mates who refuse to light a light. Presumably there are whole underground cities with nary a light source to be had...hmm, that just doesn't jib with typical fantasy world visions. It also makes dungeon delving a different thing than what I want to run. So, I'm going to look deeper into this topic in this post and make sure I know how I want to handle this topic.