PS5’s DualSense controller doesn’t appear to work natively on PS4 but, curiously, it does connect to PS3.
With PS5 peripherals on sale in the US, YouTuber Midnight Man (as spotted by VGC) managed to unbox a DualSense and test its features. In the video, we see the PS4 failing to recognise the DualSense using a USB connection, and recognising a wireless controller in its Bluetooth menu, but not allowing control once connected.
However, when connected to a PS3 using a USB controller, the DualSense is recognised and can navigate the console menus. ResetEra user iceblade has previously said that