Comment by Mawr
It's fast enough today. Metro Exodus, an RT-only game runs just fine at around 60 fps for me on a 3060 Ti. Looks gorgeous.
Light mapping is a cute trick and the reason why Mirror's Edge still looks so good after all these years, but it requires doing away with dynamic lighting, which is a non-starter for most games.
I want my true-to-life dynamic lighting in games thank you very much.
> it requires doing away with dynamic lighting
Most modern engines support (and encourage) use of a mixed lighting mode. You can have the best of both worlds. One directional RT light probably isn't going to ruin the pudding if the rest of the lights are baked.