iPhones are becoming through and through replacements to computers. I for one only use a full on laptop/desktop to game. Everything else I accomplish from my “phone”.
I used to spend a lot more time on a Mac even at home not necessarily to work but just for chilling out and since I've become a father I can't use my Mac anymore and I spend a lot more time on the iPhone. The iPad would be great too, but is set to my wife's accounts so I only use it for browsing, while everything related to social network or mail is on my iPhone.
It is pricey, really expensive, but it's the most important device I use and there is so much difference between it and a device from 2-3 years ago I can justify spending so much on it.
My 2011 iMac is my daily driver and I have a 2016 MBP, I can use a Mac from 6-7 years ago and be fine but not an iPhone, not yet.