The tipping point for me came when I pulled myself away from the phone and used the watch more.
I used to be able to walk to work, and I remember the day I put my phone in my backpack, purposely making it even more inconvenient for me and basically forcing myself to rely on the watch. I got a text from a coworker on the way in, and I swiped to respond with a brief, "Ok" -- which was all the response I needed -- and it felt quicker and easier than doing the same on the phone. I got another text, which I decided didn't need a response -- but checking it was as easy as checking the time on a regular watch, and quicker than pulling my phone out of my pocket. As I was leaving work, I invoked Siri on the watch by saying, "Hey Siri, tell my wife, 'I'm on my way home now,' period," and with no further action on my part, Siri automatically sent "I'm on my way home now." So fast, so simple, and I didn't need to break my stride.
Another day, I went shopping with my wife, and I put my phone into her purse. I was able to avoid wandering around, tailing her with my nose in my phone, like so many other husbands and boyfriends do these days (seriously -- go watch them at a shopping mall sometime). But, I was also able to acknowledge a couple texts from coworkers and take care of a little business.
When I'm home, I can park my phone on a bookshelf or end table and never touch it. When we're visiting Grandma on the weekend, I can get my hockey team's updates on the watch without looking like I'm avoiding contact by browsing Twitter on the phone. I can innocuously get walking directions to the next meetup. I get schedule updates via our Slack channel in the middle of lunch and then tell my classmates as if I were a psychic (which we know is NOT true!).
The watch is less obtrusive than a phone or, IMO, earbuds. It doesn't make me look like I'm blocking out the outside world like earbuds do (earbuds are, or should be, the universal sign for "Don't talk to me"), and because the interactions for a watch are inherently brief, it doesn't take away my visual attention, either. When I use it not as an accessory, but instead of my phone, I found out what it's good at doing -- and it's good at doing a lot without taking away my time and attention.