Love the comments.
If "for me" is included in your comments on why an iPad won't replace a Mac for you, then "For some people, iPad Pro is a replacement for their computer," doesn't include you.
Yes, you can't develop iOS apps on an iOS device. So what? Developers are probably the group of people who make the absolute least sense to use a locked down environment for their profession. Who knew?
Basically, this.
Its horses for courses.
If someone has a computer, but all they use it for is to surf the net and play solitaire, then for them an iPad could easily replace their computer. If someone uses a computer to do high end video editing, then it obviously wouldn't.
For me, the iPad is just a great thing that is mostly used to consume stuff, sat on the sofa, where its more comfortable than a laptop. I do have a great use case where it absolutely complements the Mac - as part of my work I use it to add annotations to graphics with the Apple pencil using Adobe apps, that I can then send to Illustrator on the Mac. Adobe sometimes get a lot of stick, but for me this has been a massive improvement on my workflow compare to accurately adding lines using my Wacom tablet.