Too many people are eager to share their own view as though it was the only one. Sites like this one are somehow like... irresistible bait to these people. I don't know what it is that drives people to come to an enthusiast site to talk down on the thing people are enthusiastic about. It's like seeking someone out just to say you don't like their choice of shoes. Who would even do that?
Anyway, all I can say about laptop replacement is that I don't even use a laptop. I don't need one. No reasonably portable notebook comes anywhere near the performance of my iMac and I wouldn't want to maintain multiple working environments anyway. But, I will be using my iPad Pro, from time to time, to remotely access this environment. That's why I'm interested in the pro. I want the larger screen for this reason. I like other aspects too, but, screen size is the most relevant thing to me. I will use my iPad Pro to do peripheral tasks for my profession outside the confines of the office. Of course, I could do it with a notebook, but, I enjoy iOS and iPad. I enjoy the integration it offers, the quiet it offers, the power without fans it offers. It's an elegant user experience to a point, even at a "professional" level. But, I mean, so is a pencil and pad.
The fact is, I already "replaced" the notebook computer with iPad Mini, but, iPad Mini is really not appropriate for remote desktop sessions accessing IntelliJ IDEA or Visual Studio. Furthermore, I often find myself setting up my iPad on its stand and using it there, tapping to move on to another page or watching a video/webcast on a topic of interest (as a developer, one spend a large amount of time learning new skills and sometimes the best resource is, unfortunately, a video.) The reality is, I don't need the device to be ultra light. I really just prefer iOS devices for the way it feels to use them compared to other platforms. I may mention that I am not personally opposed to the idea of a merged OS or something like what MS does with Windows and tablet mode, but, I also recognize how negatively this would impact the availability of software for either environment and respect Apple's position on the matter. I would probably be attracted to the Surface Pro or Surface Book if they weren't running Windows. Windows is a liability. And Windows suffers from tablet mode app shortage. Frankly, I have a ton of software on iOS that I already really like and would be frustrated constantly by its absence on Windows.
Finally, I personally know people whose computer use for personal reasons never stretches beyond their phone at this point. They only use notebooks/desktops for work or when forced by school, etc. For these people, the notebook is already replaced and it wasn't by iPad, it was by iPhone. All an iPad is for these people is a bigger phone. Which is great! No need to complicate it further than that. We love our phones and it's not just because they come everywhere. It's because they work SO WELL compared to desktop computers. User experience within the scope of tasks commonly performed on phones is light years ahead of desktop computer UX. iPad is just an extension of that experience with a bigger screen making some things more practical or simply more enjoyable.
Apple is not at all claiming that iPad Pro is replacing notebooks and desktops for everyone. Pointing out how it won't replace these things for any particular use case is about as far from useful, interesting, or profound as you can get. Frankly, it's tiring. It's far more interesting to hear about people who have moved to iPad in situations that are maybe not so obvious.