When I first read about this feature, I though it was pretty lame. The watch connects to the phone via Bluetooth, so you have your phone with you in any case. So big deal that you can do some limited stuff from your watch when it’s easier to just whip out your phone and have the full app available.
But then I got to think - I go running from home a lot in the early morning or early evening when there are either nobody at home, or everyone is asleep. So I have to always take a key with me. I don’t run with my phone but my Garmin connects to the phone in the house via Bluetooth when I am still outside stretching after my runs.
So I have now found a use case for this feature! I created a routine that opens the garage door. This allows me to pull the locked doors closed behind me when I go out for a run, and then come back and open the garage door from my watch, without having to bother to carry keys with me. Pretty cool :).