Final Fantasy 16 producer and 14 director Naoki Yoshida wishes everyone played games on the same console.
That model has been tried in the past and it didn’t work because no one was making any licensing costs from the games produced to pump into R&D to progress the platform. Remember the 3D0?
The reason a PS can’t play an Xbox game is because Sony don’t have access or the legal right to implement the hardware or software environment that MS have patented for the Xbox.
Except Valve is doing with the Steam deck. And if Google could be bothered to take it seriously, Android could also be a contender.
The latest Xbox and PS consoles are basically x86 PC’s with a AMD CPU and a locked down operating system. The Xbox uses a system based on Windows 10 (games are running in separate OS containers, basically Window VMs in HyperV) and the PS is using Sony’s Orbis OS, what based upon FreeBSD.