It looks absolutely terrible on PS4 and runs at a very unstable 30 fps at most. You'll probably be experiencing drops to around 15-20 FPS during some of the bigger firefights.
It's by no means unplayable, and everyone who says so is way too entitled imo. It plays on 7 year old hardware and you can definitely enjoy the game on PS4.
I enjoy playing it and since it will be carried over to the PS5 library I won't refund it.
BUT I advise against buying it for PS4. Put the money for Cyberpunk aside and once you've got a PS5 or a good PC, then consider buying it.