There’s really nothing that can substitute for the certainty of actually watching someone struggle to use your design, but these analytical approaches are quick ways to get feedback, and suitable fallbacks if working with actual people isn’t feasible.
I really agree with the reading’s point that there’s nothing like watching a real person struggle to use your design. I’ve experienced this in group projects where our design seemed perfect on paper, but once we saw users getting confused or stuck, we realized how many assumptions we had made. It’s such a valuable reminder that analytical evaluations and heuristics can only go so far—real user interaction reveals issues we’d never anticipate ourselves. This reinforces why usability testing with actual users is irreplaceable for meaningful feedback and improvement.