Just how good is the Unreal Engine 4?

Epic Games has recently shown off the ability of its latest Unreal Engine: capable of producing textures and details in scenes that rival reality.  This short animation, designed by Quixel studio was produced in 4K and demonstrates how realistic the lighting technology inside Unreal Engine 4 has become.  Will it be very long before we are able to add such convincing lighting effects and textures to our images in post-production, or how about an augmented reality app that could be used to experiment with studio lighting setups?

Quixel (2019) Still from the animation Rebirth

Quixel (2019) Still from the animation Rebirth