https://thenextweb.com/gaming/2019/12/18/xbox-series-x-ps5-backwards-compatible/

The Xbox Series X, Microsoft’s entrant in the next-gen console war, will have thousands of games at launch thanks to the console being completely backwards compatible from day one. Is this something the PlayStation 5 should consider?

We’ve known since the Project Scarlett reveal that the console would have backwards compatibility, and Microsoft reiterated that fact during its reveal of the console at the Game Awards. Xbox head Phil Spencer later told GameSpot that this would be a feature at launch: “We wanted to make sure we had that, day one, we could deliver on the compatibility promise, and so I’ve been playing quite a few [Xbox 360] games on my [Xbox Series X] and Xbox One games on the [Xbox Series X] and that’s just to ensure that we can be there day one.”