The article agrees with you that, for learning tools, "on-demand" or "just-in-time" learning is advantageous. This applies for the things that you point out as being commonly cobbled together. However, for learning whole concepts like "AI" or "cloud development," these things are rarely cobbled together and require one to learn how to think through a whole new lens. The concept is larger than any one tool, and the idea is that thinking more broadly will be advantageous in the long run