When Siri first came to the Mac in macOS Sierra, the obvious way to use it was to click the Siri icon or trigger the keyboard shortcut. That worked, but it also made Siri feel less like an assistant and more like another app you had to manually open.
The better idea was hands-free access. If you were already using voice commands on iPhone, it was natural to want the same style of interaction at the desk: ask a question, start a timer, look something up, or trigger a simple task without reaching for the mouse.
This archive post originally pointed to Daniel Portis walking through the setup. The practical takeaway still holds: voice assistants are most useful when the friction is low. On the Mac, that means thinking through where the microphone is, whether the machine can hear you reliably, and whether hands-free Siri actually helps your workflow instead of just adding another always-listening surface.
I still think this kind of feature is worth testing, but I would treat it like any other automation: if it saves a real step in your day, keep it. If it becomes a novelty, turn it off and move on.
