No PS4 is winning because of their exclusives. When you have Uncharted 4 for example as GOTY it makes it very hard for people not to choose your console.
The reason the hardware is important is because games like Uncharted, Last of Us etc (which are system sellers) stand apart from the likes of Witcher 3 because of the ability to use the superior hardware to product superior graphics. I would argue this is just as important as the game play. But again not for all games just these specific type of games.
Yes, we agree that PS4 as a platform is more succesfull than the xbox. I disagree it has much to do with hardware specs.
Yes, PS4 has a slightly better GPU but even if PS4 and Xbox one shipped with hardware where xbox one was slightly better it would not affect the current market share that much.
Up to a point superior graphics are created by superior artists and animators. Using engine and art assets by superior programmers.
Uncharted is so good because of Naughty Dog, not because their platform happens to be PS4.
Sony has played their part well, whereas Micrsoft fumbled the Xbox one launch and positioning.
The Witcher 3 is much more open world than Uncharted 4. I don't think this is a matter of optimising for the specific hardware, it is mainly the trade-offs inherent in a large open world game vs a linear game with small well defined levels. They each optimise for different values.
The reason the hardware is important is because games like Uncharted, Last of Us etc (which are system sellers) stand apart from the likes of Witcher 3 because of the ability to use the superior hardware to product superior graphics. I would argue this is just as important as the game play. But again not for all games just these specific type of games.