I feel the term "killer app" is being misused these days. A killer app isn't a game or software that demonstrates the potential of a product, rather it is a game or software that makes the masses want/buy the product. Wipeout series is great I'm, but too niche to be considered a PSVR seller to the masses.
There's only a few killer apps in videogame history...
Super Mario Bros
Super Mario World
Sonic the Hedgehog
Super Mario 64
Final Fantasy VII
DVD (for PS2)
I might be missing one but that is the echelon of true killer apps that made those systems fly off shelves.