I used to say the same things. Then I got my smartphone a few years back.
For example, I was at this scifi convention last weekend. There were tons of things on sale from vendors. Whenever I had a question about something's value, I just took the phone out, googled it and in 3 seconds, it was on my screen with ebay prices, collector value, customer reviews. Like, my phone's got 4GLTE, sometimes it's faster than my computer for looking shit up. Could I live without it? Well yeah, of course, but it's so immeasurably convenient for daily use.
Yeah, I dislike that it's basically this giant exposed screen and I miss the design of my flip phone, but functionally my HTC One is irreplaceable to me.