On p183 of the PHB under Vison and light it says:
The most fundamental tasks of adventuring— noticing danger, finding hidden Objects, hitting an enemy in Combat, and targeting a spell, to name just a few—rely heavily on a character’s ability to see.
...In a lightly obscured area, such as dim light, patchy fog, or moderate foliage, creatures have disadvantage on Wisdom (Perception) checks that rely on sight.
The first paragraph seems to indicate that lighting affects combat. However, the second paragraph specifies that only perception checks are affected by dim light...
The Perception skill seems to be more about finding hidden or obscure objects instead of identifying threats in combat..
Does dim light give disadvantage in combat?