The PS4 will go down in history as one of the consoles with the longest high caliber first party support. 9 years old and gets God of War Ragnarok. I guess you will not need to buy a PS6 3 or 4 years after it's release.
This is my most anticipated game right now and nothing even cones close. It is a bit concerning, that the norse myth will just get two games. But let's hope it is going to be an absolute rollercoster.