What are the benefits of a Hybrid game?

A "Hybrid" game is a video game that compromises of two or more genres. For example: Animal Crossing is both an adventure and compilation game. Minecraft is both an adventure, strategy and (partly) action game. But, what are the benefits? And, if you could answer this as well, what are the disadvantages?

Animal Crossing is a hybrid? I was sure Animal Crossing only has 1 genre; Life Simulation.
Minecraft is classed as Sandbox, meaning you're pretty free to do what you want, it isn't classed as strategy, action, adventure.
If this is what you're classing as hybrid nearly every game is hybrid then.