Like everything else, scans have their use. While I have never used scans to hide any problems with coins, I do use them for group pictures in lots. I also provide click-to-enlarge pictures that are large enough to grade by. I always photograph single coins. Take a look here and see what I mean. These are all scans and represent these coins very accurately:
https://goccf.com/t/15439There are sellers who do their scans in black and white instead of full color which hides problems. All of my scans are done in full color and I haven't had a complaint yet. I compare them to the original coins and only use them if they are accurate.