Sony's first party sales this gen have been really impressive, there is no denying that. I never imagined they can reach these levels.
With that said, they are not on Nintendo levels, maybe they will be someday but for now they arent.
Another thing with Sony is they love to heavily bundle their games. Games like the Last of Us Remastered, Uncharted 4, Horizon and God of War have all been heavily bundled. Just last year all 3 of God of War, Horizon and Last of Us Remastered were included in one bundle!
While for Ninty Ive only ever seen them bundle Mario KArt heavily.
And when I talk about bundles I typically mention only ones where the game is basically "free" and not when the bundle equals console + game price.
My ps4 was bundled with last of us remastered, driveclub and uncharted 4. I have to admit Sony do some amazing deals.
No denying the value of the bundles!
But they do inflate the sales numbers of the software.