[umpc]

Why would Apple test every 3rd-party compatible screen?

If they don’t test, components will break. If they don’t change APIs, components won’t be able to improve sufficiently.

In this case, there are only two actual solutions from Apple’s perspective, and they’re both ‘bad’ for customers:

Restrict users of 3rd-party screens from upgrading their devices, even when breakage may not occur, or, let them update and take the risk.

Technical debt, likely caused by time-pressure before releases, is expensive when it can’t be left behind.

Apple also doesn’t have to support much 3rd party hardware because their phones are the only built to run iOS.

I would imagine that Google’s processes are better equipped to support more hardware and for longer durations.