https://wccftech.com/ps5-vrr-support-to-be-added-in-future-software-update-sony-confirms/

Owners of HDMI 2.1 equipped televisions couldn't have been happy to learn that PS5 VRR support is not currently available at launch, despite Sony's next-generation console technically supporting the HDMI 2.1 specification. This is even more of a disappointment because Microsoft has supported Variable Refresh Rate since the Xbox One X, which launched three years ago.

Wccftech readers are very familiar with the technology, first pioneered by NVIDIA with G-SYNC gaming monitors and later by AMD with FreeSync. The DisplayPort spec has included Adaptive-Sync since 2014 and now, at last, the latest HDMI 2.1 spec enabled it as well.