Made the most powerful console, whilst in constant communication with first and third party devs to build it around what they wanted
Features like Remote Play, Share Factory and the best new feature across all new consoles, Share Play
Made big efforts with indie developers to ensure that they had a constant stream of new smaller titles every week
Popular around the world. This helps make sure, for example, that good relationships with Japanese devs are maintained, so that game series like Tales, Yakuza, Ys, Persona, Dragon Quest etc come to Playstation and generally nowhere else on home console or PC
Released some good exclusives, such as inFamous and Bloodborne
Have a lot of exclusive games coming thanks to having a strong and diverse first party stable, and funding third party stuff. Also have the most studios who have unannounced projects.
Priced the console well, without bundling in a useless peripheral that 1% of the gaming population wanted.