A part of me doesn't agree with the author that Apple's main goal is to make it so difficult for people to repair their own devices that most people just buy another phone.
Personally, I do a lot of DIY things and have always preferred to have the best quality tools for the jobs. I own several vehicles, none of which have under 100k miles on the odometer, and I do 95% of maintenance on them all. They range in age from 47 years to 7 years so I need to understand old-school mechanical things and new electronic-controlled things and as a result I look for tools that simplify troubleshooting and parts replacement.
I build with wood and metal too and am familiar with carpentry and cabinet building, stick frame construction, welding and cutting various metals, and finishing the resulting constructions so that they last a long time. All of this requires tools made specifically for the task. I am currently rebuilding a fireplace and hearth and refacing it with slate and basalt so I don't need to stare at all that ugly 70's brick.
I also dink around with everything that fails in an effort to understand what happened and whether it is an easy fix or it is time for a new gizmo. I have repaired our refrigerator, our dishwasher, clothes washer and dryer, and a number of small appliances. My usual method is to disassemble the device and troubleshoot until I find the failure point. I use online videos and manuals, blog and forum posts, etc to keep me moving in the right direction.
I have also replaced the battery, hinges, and screen on a MS Surface device and a couple of telephone screens. For this work I used iFixit as a resource and everything went smoothly as a result.
I still use my Windows Phone because it is a great phone and it still works, though that will end later this year when the 3G networks are removed from service, so I will likely end up with an iPhone.
So far I have not needed to replace an iPhone screen or battery on any of my family devices, but if I end up needing to do this in the future I am pretty sure that I would just go through the process that the author documents since he was able to accomplish the task with no serious issues. That's the actual goal here.
The fact that a user is able to employ exactly the same tools Apple uses without having to buy those tools and the entire procedure is documented with photos and concise descriptions of operations is a huge plus. I don't have time to examine every device or gadget that glitches or fails in an effort to guesstimate what I think needs to happen to make it work correctly.
I think this is a bargain for those of us who are inclined to repair our own devices.