Why we can't just let per pixel lighting unlimited?

I have simple project, which is too dependents of pixel lighting for gameplay, it's third person shooter with horror atmosphere. My concept of making this game is "Whatever is not reachable by light, is not visible" The point is that I use lighting as an element of horror, where the enemy will surprise the player from darkness. (I wrote this by using translator, sorry if kinda weird)

I figured out I must set pixel lighting count limit so when I go to low setting, it breaks the dark area because Vertex lighting looks so different (I know the reason). I saw many games had many-many pixel lighting (gta, outlast, resident evil 5/6/7 and so on), is pixel lighting consumes many performance? we can see many realtime shadows, we can do many shaders manipulation on every frame we saw. but why we can't do with lighting? CMIIW

 

Nothing, I found my solution is use deferred lighting