Because all the parts are paired. Hugh Jeffreys has an interesting series where he buys two new phones and swaps the parts. Basically nothing can be swapped without breaking core functionality. Swapping a screen, for example, loses true-tone and auto brightness.

This can be fixed by replanting a tiny chip from the old screen to the new screen, requiring extremely precise micro-soldering skills that the average repair shop doesn’t possess.

Yep, absolutely true -- I worked on the project ("FDR / New Deal").

It was originally supposed to prevent a repeat of the Hon Hai Zhengzhou incident where a team of line workers mixed/matched parts from units that failed QC and sold the Frankensteined units on the grey market. (Massively oversimplified, but that's the general gist)

The resulting near-total inability to swap screens/buttons without knowing someone with FDR update access was seen as acceptable collateral damage.

By who? And did you see it that way?

If that project came my way, it would have been a hard no, go find someone else. You literally implemented the most public unfriendly feature I've seen in a long time. That's one of those cases where sometimes the cure is worse than the disease.

While I understand we are all entitled to differently prioritizing ethical red lines, it saddens me whenever I see the public suffering for the sake of increased corporate profits.

...and it is only the company that gained anything. The extra parts on the market would likely have driven prices down, making the handsets less high dollar desirable theft targets. Instead; user servicibility plummeted, planned obsolescence ensured the path of least resistance was "buy another", and the accountants likely beamed at the improvement to the bottom line while the execs patted themselves on the back for a job well done securing money that otherwise "would have been left on the table".

Oh well. So it goes.

It took the theft of phones from honest folks to make those 'extra parts' available in the past. I personally don't want these 'extra parts' on the market even if it ends up increases repair prices for everyone.