Haha the adhesive is the least of my worries. The battery is individually paired with the phone meaning if you got 2 identical iPhone 14s and swapped the battery between then youll get a bunch of popups and errors about "non genuine apple parts" and it disables features of the phone too. This practice is called serialization.

It is because of that we have to butcher the battery, remove that special little board (this is the part that is serialized) and Frankenstein the new battery together and then reprogram it (the battery board keeps track of battery health and without reprogramming it will register the new battery as bad health).

Same thing with tons of the components, new screen? No auto brightness. New front camera? No face id. New back glass? No wireless charging. No home button? No touch id. Hell, repair your iPad? No drawing straight lines. (Seriously your apple pencil will no longer draw straight after repair)