Exactly and this is why Apple pairs the front part (and various other parts) to the motherboard. To make it easier or something. Got it
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".