So they don't leave and make games for others? Fuse and Sunset Overdrive exist. 

Im not entirely sure why Sony hasn't bought both Insomniac and Quantic Dreams, I asume it is because they don't want to sell, id be surprised if Sony hasnt tried.

Gigantic waste of money. The dev already makes exclusive content for their platform and has a sizable team, so a buyout would be expensive with not a huge amount to gain. Insomniac also have never produced a breakout hit. They've released their share of well liked, but commerically unsuccessful titles and a mix of titles with reasonable, but not exceptional sales. Sony would do far better to fund a team like Bluepoint to make a full AAA title. Key players at Insomniac likely also want their freedom, so a buyout could see senior staff departing, and along with it the soul of the company.

I think if these studios were wanting to be bought into Sony First party I would like to see Insomniac, Quantic Dreams and Supermassive Games.

No they shouldn't. After what they did to Studio Liverpool, Evolution, Incognito, and Guerrilla Cambridge, Insomniac would be far better off staying independent.

They were aquired by a film company. Nordisk.

Yeah, it would require talks to make that work. I still think it would be a much better purchase than Insomniac though.

way too expensive and they betrayed sony by making overdrive for microsoft

Betrayal? Really? Did they swore allegiance to Sony against their "enemies"?

It's not a fanboy war, it is a business. Of course they are allowed to accept other projects if they have free resources for that.

Than games like Sunset Overdrive wouldnt exist.. is that what you want?

no. sony was fine with sunset. they just wanted the IP. inso wanted to keep it

if sony had them. they woulda made it because duh they would own the IP