Many people complain that NVC sounds unnatural. This is because it is like learning a new language. It sounds unnatural when any native speaker teaches someone their language, because they speak slowly, in simple phrases, and repeat everything at least twice. That is exactly what Marshal did when teaching NVC.
Once you are fluent, it sounds very different and works beautifully. I've occasionally offer help to couples on the verge of breaking up, reworking what they are saying into NVC, and the effects are profound.
Couples on opposite sides of the room, who can't look at each other, end up tightly holding each other, crying together. They feel understood for the first time and understand the pain in each other that motivates each other's hurtful feeling actions.
Then I start teaching them to do it themselves. When they do, the relationship improves. When they don't, they keep needing to come back again and again, and the relationship slowly dies.
I still tend to listen to the full lecture on YouTube about once a year or two as a refresher. As far as I'm concerned, this is one of the most important life skills anyone can learn, and NVC should be taught in all schools.