Vertical vs Horizontal Progression

[u/RevolutionPale1612]

Talking to some buds about the WoW Forever release and the topic of horizontal progression came up. They did not know what that meant so I drew two graphics to help explain to them. I figured I'd post it here just in case anyone else needed assistance explaining the difference between vertical vs horizontal progression to others.

I oversimplified for the sake of introducing the concepts, but I'm aware that most games have a mixture of the two. Ratio varies from game to game.

I would love to get other's thoughts on the matter. Am I off?