Does 'moderation' work in practice? What do prominent WFPB doctors and nutritionists say?

Dr Brooke Goldner (physician & psychiatrist) strongly advises against moderation.

Chapter 5 of Dr Esselstyn's Prevent And Reverse Heart Disease (2008) is titled "Moderation Kills". Why does he say that?

Whole Food Plant-Based guidelines often use a traffic light system: red, yellow and green. Why moderate the consumption of yellow light foods? How to do it?

Is 100% plant-only WFPB better than 95% or 99% plant-based WFPB?

Jeff Nelson narrates the story of his dad.

Dr John Kelly explains that strict adherence to low fat Whole Food Plant-Based guidelines may be the key to cancer prevention.