After watching the video in high resolution, it doesn't look particularly great. I would guess the game uses upscaling, from an estimated 360p base resolution, and the framerate looks like 17-25 fps. If that can be judged from the video...
Ugh... I don't know, but assume if they had chosen another engine than UE5, it would probably look better and run better. I mean it looks like they are now trying to press UE5 into every little hardware device, and can only make that happen by making the game ugly.
Leaked gameplay footage for Star Wars Outlaws shows pretty consistent gameplay, though at a lower resolution. The footage is said to be from docked mode so it would be interesting to see how the game runs in handheld mode.