What makes you think we will ever reach even close to perfect photorealism?
I should also mention that this goal of perfect photorealism (like everything in life) isn't a solid line.
"Hitting that goal" will mean nothing more than us hitting a threshold in visual quality at which most
people won't be able to tell whether something is real or Digital AND/OR developers feel they are
able to express themselves with few enough restrictions. (Nintendo is already at this stage!)
Whether we hit "perfect" photorealism is irrelevent (The event will probably not even get much media attention).
The day visuals are "good enough" to fool anyone - that's the day "the goal has been reached". That day is soon.
My humble opinion.