Arkit camera feed has low resolution comparing to the iPhone camera

Hello,

I have an AR project that uses ARKit. I did some tests in an outside area with my iPhone 8, but I was surprised when I noticed that the camera feed from my UE4 app has really LOW resolution!
I compared it with the video of the same scene using the device camera, and the difference is big.

So is there something we can do to improve the camera feed? If no, what’s the point then to use ARKit at the moment! because we must have an acceptable video quality to be able to use AR.