PS4 Pro & Nintendo Switch own 2017 because they have EXCLUSIVES. XB1/Scorpio has no more exclusives since 2014 because every game turned into a multiplat making Microsoft's console pointless.
SEGA (as one of consoles) still exists? Lol.
And pretty much what Frayhua said X1 committed sudoku in 2014 and now whole "war" is just between Nintendo and Sony.