If you watch videos of people doing iPhone screen replacements, you can watch them peel it off easily and then replace it when they put the new screen on.
I am a bit surprised that someone would want to argue with a person who runs shops that do this for a living, but maybe this explanation will help other folks understand.
Also, I can’t reply to your other comment, but the iPhone 14 that is sold in the United States does not have a SIM tray.