Throughout Sony's reign this console generation, their first-party studios have arguably been their strongest and shiniest asset.
After losing built-in third-party support during the PS3 generation, they began grafting a group of in-house developers that has remained solid and untouched throughout the current PS4 era (asides from Guerilla Cambridge shutting in 2014).
It's not a secret that Microsoft whipped out their wallet this past year to take their unbalanced first-party line-up and chisel them into a jaw-dropping bevvy of incredible talents that now stands count-for-count with Sony's studio numbers. It will take a few good years for the dividends to pay off, but the gauntlet has been laid down.
Unlike Microsoft, who threw their Bill Gates money at a slew of distinctly individual and eccentric developers (with most not holding historical ties to Microsoft), Sony's approach has always been different; they tend to nurture a tight-knit and loyal relationship with a second-party studio over the years, then when the next natural step is ownership; they seal the deal.