The Big Three of Gaming

SOny- JApan

Tencent- China

Microsoft- USA

Microsoft becomes the third with the acquision of Blizzard Activision , Microsoft bought Bethesda last year

The Microsoft XBox was meant to be an industry leading dominator, but with the Imagination of little nintendo side the industry first high end gaming marketeer Sony , the space is little. So Microsoft is buying big studios for raw cash. 

Now I recall people saying, when Disney bought MArvel + Lucasfilm for hundreds of billions it was a wise choice long term. This is the same idea here with Microsoft. Right now, it may seem silly or incompetent. But, these third party publishers are not just their main games. Microsfot said, they will treat games on a game by game basis. So, big titles from these publishers will be as before, published everywhere. But little titles... may find their way to xbox more.

In the same way, Netflix had to reorganize when the content producers each made their own streaming platforms, forcing netflix to invest in their own shows. 

Nintendo will be safe, cause nintendo has never not been proprietary for the most part. But , Sony will be wary of this.