> while there were no technical restrictions preventing me from replacing the broken camera, the screen was glued in in a way making it very difficult to open without smashing.

You just presented a technical restriction, didn't you?

> but having an official location with official parts is actually more useful than being able to do it yourself but not being able to get parts.

I disagree. This is not so much about DIY-repairs, but about a free market for third-party repairs, without which Apple can force people to pay as much as they want.