Comment by gmueckl
11 days ago
I think this is because of how extremely cleverly they picked the art style for the game. You have a lot of diffuse surfaces for which prebaking the lighting just works. Overcast skies allow for diffuse ambient lighting rather than very directional lights, which force angle-dependent shading and sharp high contrast shadow outlines. And the overwhelming majority of glossy surfaces are not too shiny which also helps out a lot. All of these are believable choices in this run-down, occupied, extremely dystopian world. And the texturing with its muted color palette pulls it all together.
There's been a rumor going around that developers move away from prebaked lighting primarily because it complicates their workflow.
Prebaked lighting is a rather crude approximation that only looks good in certain scenarios. Correct dynamic indirect lighting provides a much better integration between different scene elements and better spatial cues. Movable and static objects can share the same lighting model and you don't get an immersion breaking situation where e.g. the one door that you can open in a hallway stands out because it has worse lighting. It is an overall win, not just during production.
That rumor didn't exist 20 years ago when Half Life 2 had come out. Pre-baked was the only way to go. Now we have performant ray-tracing.