Along with backward compatibility and Quick Resume, another alluring feature that the Xbox Series consoles have is FPS Boost support for older titles. This has pushed the frame rate up to as much as 120FPS for many classic last-gen games such as Battlefield V, Dying Light, and Fallout 4.
The latest game to receive Xbox FPS Support is Dark Souls III, as the brutally punishing game now runs at a consistent 60FPS (up from 30FPS through backward compatibility). Interestingly, Xbox director of product management Jason Ronald mentioned on Twitter that enhancing Dark Souls III required a "brand new technique," but this wasn't touched upon in detail.
Thanks, Windows Central.