Thanks for the article! It is interesting but to be honest it still does not tackle or answer my needs of a laptop. However nevertheless we agree that it depends on what we use our laptops for and how. Only once we know this, we can now whether the iPad could replace it or not.
For example I understand why some people do not want to organize their files on their own. It is cumbersome for them. For me it's a need. I know the best how I want to organize my files and I could even organize them differently at different times based on my specific needs and I need to have that choice. If I don't have enough storage and want to delete something I want to know everything that is stored to decide what to delete. In general the systems that decide to decide for me and think for me do not work out. I often have different ideas and have to spend hours on trying to fix the system's shortcomings in doing things I did not even ask for.
And I don't want to rely on Internet connection so I rarely use cloud services for storage.
I would also say it's a matter of balance. Having multiple devices that serve only one sole purpose is overkill. Having one device that does everything is a mess and it's too complicated. Having too many open windows can be a mess for some I agree. On the other hand having only one window open for me is a restriction I dislike. I can't find an app that can do everything I want. And even if I can it will be too complex that I will have to read the manual for it every 5 minutes. And that in itself begs for a second window.
I guess it's also a matter of work. I have tunnel vision. I can have 20 applications open and still focus on only one if it's enough. That was never an issue for me. I do use big screen though. And even 12.9 inch iPad Pro is not big enough for me to replace a computer. Even if it was easy to add another monitor (I still maintain the fact that easy means no dongle and no app usage) it would take a toll to the battery. This is not a laptop that you can keep on power source all the time. This is Lithium battery that has certain mount of charge cycles before getting bad. The iPad is a device is not meant to be plugged in power source all the time like powerful computer. The amount of work I do on a computer is however such that I will have to charge the iPad at least one day. Sometimes even more.
It's true that multi tasking is now better in iOS 11 and 12. Still though it's easier to copy/paste image using a laptop and a mouse than using drag and drop on an iPad. When you have to do this numerous times a day, the time you are slowed down piles up. Also if I work for something and I need images I want to be able to store those images together with my other text files. Not in the Photos folder. I can't do that in iOS. I don't store my files by types, but by areas. Say I am working on a Postcard. I will store the sketch that I found in Internet (suck at drawing), the improved sketch (sometimes it needs tweaking), my annotations about the different layers I plan to use, the reference photos and any color palettes ideas in one folder with the result image. Not in a common photos folder.
One last thing - performance is really subjective. The iPad I have (6th gen) has decent geekbench marks. It still reloads tabs like crazy though and if you ask me that is not good performance. So when I hear someone saying that the iPad is more powerful than laptop I would answer it depends on how you use it and what you measure as a good performance. It might have great performance for certain tasks and poor for others. If you don't do tasks with poor performance you would be satisfied. If you do them often, you won't be.