Obviously Sony here. Nintendo's stable of IP has barely changed in generations.
Zelda
Smash
Mario Kart
Wii (X) [dead IP]
Donkey Kong
Mario
Metroid
Pokemon
Punch Out!!
Starfox
Animal Crossing
Kirby
Fire Emblem
Splatoon
I may be missing one or two, but most of these (Sans Wii whatever) have been around since the NES or SNES. Nintendo has consistently been pumping these titles out for decades. But do they move consoles?
Nes: about 64 million
SNES: about 49 million
N64: about 32 million
Gamecube: about 21 million
Wii: about 102 million
Wii U: about 14 million
Switch: about 36 million (and counting)
This is....incredibly inconsistent. Despite a steady stream of first party titles, nintendo's console sales are all over the place. There's a dedicated audience that buys them but they are not pushing systems to the broader audience. There's a very good argument to be made that it's the hardware that's been selling systems for Nintendo and not the software since at least the Wii.
Sony's IP on the other hand?
Gran Turismo
Twisted Metal
Wipeout
MLB: The Show
MediEvil
Ratchet and Clank
Killzone
Siren
Sly Cooper
God of War
Little Big Planet
Demon's Souls
Bloodborne
Infamous
Ico/SOTC/Last Guardian
Uncharted
The Last of Us
Knack
Driveclub
Until Dawn
Everybody's Golf/Hot Shots Golf
Astro Bot
Days Gone
Dreams
Horizon: Zero Dawn
Death Stranding
Ghosts of Tsushima
This ignores long dormant franchises Sony hasn't done anything with in a long time, such as Dark Cloud, Jak & Daxter, PaRappa, The Getaway, Mark of Kri, Frequency/Amplitude, Everquest, SOCOM, Ape Escape, Singstar, Syphon Filter, Motorstorm, Resistance, Heavenly Sword, or Warhawk/Starhawk.
Nintendo doesn't have the breadth or depth of IP to compete with this.
That stable of IP hits a broader audience than nintendo does, one that's more in line with the titles that third parties like to produce (which encourages third parties to produce titles for the system) and most recent titles have a multiplayer component that's in line with where the market's been for the past two generations.