I can't speak for the entire 8th generation because WiiU is on an entirely different level and XB1 is having hard times with 1080p but PS4 seems to be doing at 1080p but stabilize on 60 fps and/or more demanding graphs. Of course the high end PC graphics will have the edge, and the consoles will soon be outmatched by and average pc in a few years as well but this doesn't change the fact that the vast majority of the TV sets out there is and will be 1080p (or lower) at 60 hertz, which is the ceiling for consoles for a long time.
Given all that and the increased budgets of games and various other reasons, I see this generation (at least in PS4 terms) to be a long one, possibly even longer than the 7th gen).
Playstation 5 vs XBox Series Market Share Estimates
Regional Analysis (only MS and Sony Consoles)
Europe => XB1 : 23-24 % vs PS4 : 76-77%
N. America => XB1 : 49-52% vs PS4 : 48-51%
Global => XB1 : 32-34% vs PS4 : 66-68%
