We already have nanite and mesh shaders. What more do you want?
Photorealism != Perfect Realism.
It doesn't have to be perfect to be photo realistic.
Lastly people don't realize that its not the GPU power, its the tools that are created as a result of the GPU power.
For example, people praise the infiltrator demo as a hallmark.
Look at the facial, eye and hair character rendering then and compare it to what UE had in 2018.
So 2014-2018. Remember the power dynamic of these consoles didn't change from launch.
Here is UE4 from 2014 and how characters looked like and their progression as better tools were made overtime. Notice the improvements although the power level stays the same. Think of this as cutscene graphic:
2014
2016
2017
2018
So with the start of the next gen we have the Matrix characters and this Enemies demo. What will character rendering look like in 2025 when better tools are created due to the increase in power of this current gen?