Two of Sony’s best studios Insomniac and Naughty Dog came from Universal Interactive. Sony kinda was able to kick back and let such companies come to them in part due to Nintendo. This is why Sony doesn’t own Crash or Spyro but was making commercials for those products. They let both those studios make many games through that third party publisher before purchasing them.
I would say the development environment isn’t like that now. Microsoft does help small studios via Game Pass deals but if you gonna have a AAA studio now it’s likely through an acquisition. You do get some studios like 343 and the Initiative that the company forms but not many. The budgets for AAA games are too high for studios to sprout up like that. These major publishers like EA are gonna wanna own you. You not getting a plucky team of devs making successful games for years under a major publisher that’s not looking to buy them out.
Turn 10 is a good studio. Playground is also good and both of those were pretty much fostered by Microsoft. The Coalition also heavily developed under Microsoft. Microsoft has good studios they just stuck them on making the same IPs over and over again.
Any studio that makes a hit like Halo, Forza, etc. will keep making sequels over and over again.
No one wants to admit it but the reason Guerilla, and Sucker punch were able to try new IPs this gen is because their previous franchises weren’t that great. Now that they have hit franchises they will undoubtedly make lots of sequels.
Insomniac will be making Spiderman and ratchet games.
Polyphany will make more Gran Turismo, and so on
It goes for pretty much every studio. They all want a hit franchise that they can keep printing money with.