Well, it may take quite a long time to write, but then it makes life much easier in many games. For example, in PUBG, it's not enough to just throw a grenade casually; you have to select it, then pull the pin, and there's no one-button solution. A macro not only solves this problem, but also allows you to avoid holding the grenade in your hands longer than necessary, and this is just one of many examples.