Notifications and exercise tracking are my two main aims (outside of time/date/weather/step count).
I also use it for quick timers (Siri, set timer for 20 mins).
I turned off a LOT of notifications from many apps to get the balance right, so now I only get notifications of messages (iMessage, WhatsApp, Messenger), if my car moves, if the phone rings, or if my blood pressure (heart rate) is too high.
I occasionally use it for controlling media playback if I can’t easily access my phone (it’s in a deep pocket and it’s raining for example).
But what will you use it for? There are many other options. I like the way it looks, and feels, and since I got the first one I’ve upgraded a couple of times. It works for me.