I came to smartphones late, simply because for work I am always at a computer. At home my laptop is just a room or two away. Why would I need the thing?
But then, my old cell phone provider screwed up. My wife and I both had dumbphones, capable of almost nothing, but one month they hit us with a massive data charge. Now, maybe it was an error on their part, maybe it was one of us poking the wrong buttons and doing something that used a bunch of data. Either way, it wasn't intentional use on our part. We asked for them to cancel the charge as a mistake, thinking that our decade and more of being customers would count for something. Ha!
They refused. We asked again more sternly. They still refused.
We checked, and a provider with better coverage would give us smartphones and reasonable data for less per month than our usual phone lines, much less the data charge. So, we switched providers, and I ended up with a smartphone.
Now, of course, my wife's work has changed, and she would find it very hard to operate without the thing.
I'm not quick to pick up new phones - when the battery dies, or there's some technical problem, I eventually get around to getting a new phone.