Well, Maybe Sony doesn't need a "killer app." I think the way that the 3 works is
Sony = A bunch of AAA first party games designed to fit your needs but none that can really carry the console by themselves with a mix of third party and jrpgs
Microsoft = The Best online and social games that carry the platform with a mix of third party exclusive content
Nintendo = A bunch of killer apps that can carry the console but a large lack of third party support hinders it from being a success
Obviously there are exceptions and flaws to that but that's my quick summary view anyway
PC Specs: CPU: 7800X3D || GPU: Strix 4090 || RAM: 32GB DDR5 6000 || Main SSD: WD 2TB SN850