Global illumination is a very broad topic, and there are many different implementations at different levels of approximation. Metro Exodus used one version tha

Global illumination is a very broad topic, and there are many different implementations at different levels of approximation. Metro Exodus used one version that I think was one bounce only, and heavily denoised. The Enhanced Edition added probe based GI, which is infinite bounce but only captures low frequency lighting. Lumen uses surface caching, which is expensive and has low frequency temporal noise, but is higher quality yet. This video was probably covering ReSTIR GI, which is a much more advanced newer technique that has a diffuse surface approximation for multi-bounce but is otherwise almost unbiased, but might have been referring to the even newer GRIS, which can be actually fully unbiased. So... yes and no? Some GI is unimpressive, though IMO Metro Exodus' still holds up, but the cutting-edge stuff you can only see in tech demos right now.