For me personally, you don't realize the added benefit until you start using it and then stop. And yes, it's primarily about convenience, in much the same way that a laptop is more convenient than a desktop, a phone more convenient that a laptop, etc. I love how I don't have to keep looking at my phone all day, don't have to make sure it's within arms reach...probably reducing the number of times I unlock and open my phone by 75% (complete esitmation, haven't actually measured it. It's probably reduced the amount of time I spend on my phone frivolously as well--how many time do you open your phone to check a notification but then casually decide to check FB or Twitter, sports scores, web pages, new feeds, etc?
I like how my phone no longer is beeping all day long whenever I get a notification since it defaults to the phone for that when it's connected and unlocked. I love being able to quickly set a reminder or add an item to a list, how I can control playback of sound, reply to a message or take a call when I'm cooking or have my hands full in the yard or garage. Being able to take the dogs for a long walk and still listen to music and track my walk or run without bringing my phone if I choose. I like being able to easily control my musicI like how the reward cards in my wallet automatically pop up into my notifications when I'm near that merchant and can be quickly pulled up for scanning. I actually visit merchants that accept tap to pay almost daily so quickly paying with the watch is super convenient.
Is it for everyone? Of course not and most time when I'm ask by people if they should get one, I usually say no, not yet. But outright disqualifying its utility because you do so it fit into your work flow....
What's the saying, "Don't knock it 'till you try it."