One of the reasons why you should choose an Xbox One over its competition is that the system has backwards compatibility with lots of amazing games on the Xbox 360. Nintendo and Sony have chosen to go a different route and have been releasing updated ports of their old games, which they often sell at full price.
It seems that Sony is preparing to catch up with Microsoft in the next console generation and will be adding backward compatibility to the PlayStation 5, as a new patent that has been filed by Sony of Japan hints that their next system will be compatible with PlayStation 4 games.
A Reddit user named boskee discovered a patent document that had been filed by Sony Interactive Entertainment for a system which allows internal hardware to correctly mimic that of a different system.
The intention of the hardware detailed in the patent seems to be for Sony's latest machine and will allow it to play games from previous systems.
It seems that this technology will most likely be used in conjunction with PlayStation 4 discs, as there is zero chance that they will allow users to move digital games over to their PlayStation 5, or at least not without a fee.
It also seems that the hardware could mimic the function of the pre-PlayStation 4 systems, as well as the PlayStation Portable and PlayStation Vita systems. We may be seeing Sony selling all of their old games on PSN in the future, despite the lack of interest in the PlayStation Classic.
Sony was all about releasing their classic titles on PSN during the PlayStation 3 era, with some of the best games on the original PlayStation and PlayStation 2 being available for purchase, but they abandoned the idea of selling their retro games as-is on PSN in the PlayStation 4 era, in favor of upscaled ports.
The lack of backwards compatibility on the PlayStation 4 was a sticking point for many fans who didn't want to have to keep hold of their PlayStation 3 in order to play the games native to that system. It's possible that Microsoft's recent studio buying antics may have spooked Sony into adding more features to the PlayStation 5, as they have comfortably ruled over this console generation in terms of sales, but both Microsoft and Nintendo are poised for big things, and the addition of backwards compatibility to the PlayStation 5 may just be the selling point the system needs.