A staple feature of my work with offline renderes was finding the right HDRI map for the right model. An HDRI map provides lightning that that has been captured from a real world setting and as such can give extremely complex lighting features at a fraction of the computing cost of recreating them in engine.
As such I wanted to use HDRI maps as a starting point for my level lighting and created my own material for that purpose.
Conclusion – Always good to start with a solid accurate and interesting lighting base and then use the light baking system in addition to custom lighting to take visuals to the next level. This is a common practice in games like the Last of Us that see use of real-world references for scene lighting.