Its really the PS4 that is holding game dev back, that is the biggest install base of purchasers so thats what you have to dev and QA for. If publishers could get mobile users to pay $60 for a new game and $40 for a season pass then every big new game would be targeted at iPhone 6 and that would be the device that constrains power.
Still, increasing textures and better aliasing and higher FPS and res are all nice but end of the day the games we think of as definitive - breath of the wild, TLOU, GTA 5, Mass Effect, Uncharted, Tomb Raider, Skyrim, bioshock, RDR, Overwatch, Minecraft, etc - are defined by their gameplay, story, characters, writing and polish not by their technical aspects. Tech makes a great game better, it does not make a game great by itself.