As someone who struggled to understand what the fediverse even was, the email analogy was what made it finally click for me.
For me, it was pretty clear that the analogy was only about how different servers could talk to each other, and that the underlying technology wasn't equivalent. I never even considered that people might use the analogy that way until this article.
It varies per game, but my most common use is to replace the thumbstick clicks. I don't like how it feels to click in the thumb sticks, feels like I'm adding extra wear and tear to them.
In first person games, I'll often bind jump, sprint, reload, and melee to the back buttons so I can move and aim while performing those actions.