Smart watches can be pretty useful actually
I've had the Samsung Smartwatches for several generations & just got the latest 46mm Galaxy Watch.
I use it every day and find it pretty helpful.
Specifically:
NOT having to pull out my phone to check things. Basically it lets me glance and ignore which makes me more productive.
I can see with a quick twist of my wrist if the message, chat, e-mail or phone call is something I need to take or just ignore to later on.
Also seeing and dismissing alarms and job reminders.
It's also a lot more socially polite than pulling out your phone to check when you are involved in some social interaction situation.
In addition to the usual suspects such as:
Looking at the date / time
Steps taken (my doctor wants this information)
Heart rate (trainer at the gym likes to see this to find out how much more punishment they can give me).
Making quick voice note recordings of reminders on the go.