While I do think Sony is going to win and have no interest in getting the next xbox myself. I do think MS is making some pretty notable changes going into their next gen.
They will have the value win with the Xbox Series S (assuming it exists)
The performance win with the Xbox Series X
They will have marketing that comes with being the performance king
Their work into Gamepass has put it in a pretty great position as a killer service
They have purchased some pretty great studios so we will see how their games go
So I wouldn't count them out just yet. Don't forget the major issues that the 360 had with RROD and it's Kinect fetish by the end while the Ps3's end was very fap worthy. Also the 360 had paid online and Ps3 had free online.