Lets compare their value: While Fervor is cheaper and on a noncreature permanent (thus making it harder to remove), Anger provides a 2/2 body that wants to be removed
This creates a finite supply, making cards on this list, like the original dual lands, extremely valuable regardless of their original rarity
It has nothing to do with the story, and the new cards tend to be designed in isolation, not tying into anything bigger in the world of Magic
If you love the tradition of card collecting, the thrill of the hunt in a local shop, and the satisfaction of building a physical collection you can see and touch, then a physical box is the perfect choice
You can also remove -1/-1 counters, like the ones you can put on Devoted Druid to untap it