A brief rant:
when tutorials say "from scratch" or "step-by-step" etc, they shouldn't introduce ready-made scenes, because we can't watch the progress and we can't see the logic. If you say from scratch but then expect me to either find an asset online or create it in another application, then it is not from scratch. "Import the whole thing from a zip and then follow along" is not from scratch.
Tutorial makers should say "this is about coding the movement of a character" not "creating a character from scratch".
If I want a tutorial with ready-made assets, I pick a tutorial with ready-made assets.
If I want to see exactly how it should be created, tell me that and let me drown or swim.
Also, wow, the changes from 3 to 4.2 are enormous! They seem to have reducted a lot of things.
Tomcat when you can see the result at once
I agree with that in every context of learning: learn by practicing little chunks of what you know, but only undertake a big project when you are ready. If you just learn and learn and learn, it will be empty knowledge.
xyz just a marketing device
That's an acceptable practice, unless the whole thing is just a pitch for something else. I haven't read the book, but I have seen a lot of books that are just pure marketing for a class or a webinar or another service and it is very frustrating.
If there is value in the product, marketing is ok and I'd say necessary. If the product itself is the marketing, then...hm.