That sounds like a pretty solid system, but it’s not at all what the author is advocating. The author states that Docker is destined to be replaced by other containerization frameworks. The functionality differences won’t be as stark as what you’ve described, so this isn’t really a good comparison.

That being said, I’d agree that netboot + tmpfs has a lot of advantages; unfortunately, it’s not always practical, especially at smaller scales. Containers are convenient and don’t require any special hardware accommodations.