I don't know why people start threads like this. All you're going to do is kick off a pointless debate. The people that love it will grab their torches and pitchforks and leap into the fray. The "me too's" will pile on, as they're always up for an entertaining fight.
It's useful to some, others not so much. (most people just don't give it a chance). A friend of mine bought and returned an S0 4 times before he finally decided to give it more than a week. Now he couldn't go a day without it.
I use mine all of the time for Apple Pay and my grocery list (handy as hell doing that with Siri as you're peering into the fridge). Always checking the temperature outside before I head out to make sure I'm appropriately dressed (tricky time of year up here). I have used the flight pass thing a couple of times. I'll read text messages and notifications on it if they're short....more than a screen (unless they catch my attention with something important), I'll wait to read it on my iPhone. When I get to the gym, recording my workouts is motivational...helps prod me to keep going to close my rings.
Edit: Oh...and I forgot...I also use it to play music during the workouts at the gym - leaving my iPhone safely locked in my car.
Looking forward to my carrier getting their head out of their ass and enabling eSIM provisioning so I can also have the cellular convenience when I forget my phone (which I'm notorious for doing) - but I may have to leave the AirPods in the car so that works for me.
I thoroughly enjoyed my S0 for a bit over two years. Hoping I get as much or more use out of my S3.
Again, to each their own. Not everyone gets enough out of what the watch can do to make it valuable to them.