Probably not. There are only a few resolutions that car cameras have, except on expensive cars or cars with expensive head unit replacements; this comes down to the standard that the video signals are encoded.
To make things worse is that only a few companies make the optic sensors for them so the quality is fairly similar, just like dash cams.
So you can find a high quality camera and connect it to a head unit that accepts the higher resolution standard, you can upgrade the head unit and have a better quality screen to see the image, or you can replace the camera with basically the same camera.
Unless you really want to get into the weeds on understanding all the inside and outs and are prepared to spend a lot, you might as well just buy an OEM replacement for the camera you have and wait for the higher-end cameras and screens to come down in price until they are included in the car you buy.
Yeah, I found myself wanting a better backup camera when I put in a head unit with a 12.3" display and was also disappointed with reality.
Best solution I did find was to use the digital rearview mirror off a dodge or Chevy with their cameras and go through the ballache of retrofitting it into my car, but that would have cost like $1,500 IIRC.