So, software upgrades are such a normal part of the day-to-day operation of an iPhone that they happen automatically.
Thus, the iPhone is very much a computer.
Contrast this with -say- most computer monitors. There is software running in them, but -in (almost?) every case- upgrading that software requires either gaining access to programming ports inside the monitor and performing an arcane ritual that might involve specialized hardware or physically swapping out chips.
Now, I don't consider updates to be abnormal, but neither is it something I'd ever list in response to "how do you normally use your phone?"
Or my kindle. I update the software on that far less frequently.