I think this is a big deal because far and away, the most common repairs made to iPhones are replacing the front or back.
Honestly, if they cared about "best user experience", they would have done digital signature of the LCD/cable and if OEM was detected, they could display something like "Hey, someone tampered with your phone and changed the screen using OEM parts". If not, they coud say "Hey, someone tampered with your phone and replaced screen with an unoriginal one. You might see some degradation in quality because of that".