We already went through all of this with cars and car mechanics. The only difference with electronics is that people have been convinced that their smartphone, laptop and electronics in general are somehow arcane magic. Nowadays, car manufacturers also seem keen to jump on this bandwagon, since it would also benefit their bottom line to keep third party mechanics from touching their cars.

Fact is, if Apple can fix their devices, then so can a third party without much problem, it's not that hard and most of it doesn't really take any skilled labor. Apple would be better served by releasing repair manuals and selling parts (like car manufacturers have been doing) if they're afraid of having their reputation ruined by third party repairmen. That, of course, is not their concern, a third party repairman ruining someone iPhone in no way affects Apple's reputation, and it's better for Apple's business since it helps their propaganda efforts against third-party repair. Apple and other electronics manufacturers of course are not going to spend any effort supporting third-party repair until they're forced to by legislation.

For what it's worth, I think the right to repair side needs to do a better job of delivering their message. While focusing dispelling the notion that electronics repair is hard is pretty important to undo decades of propaganda on the matter, currently the environment is the hot button issue, and throwing away repairable objects isn't all that great, particularly if it's an easy fix like changing a battery. Repair needs to be included explicitly into the 3 R's somehow, either by making it into 4 R's (Reduce, Repair, Reuse, Recycle, for example) or by including Repair into the umbrella of Reduce.