Not at all.
There are plenty of options in the cell phone market that provide to the customer identical user experience. And or at least, functionality.
Hell, an old Blackberry still makes phone calls, handles texts, emails, etc. with ease.
The attraction of an iPhone over a cheaper, easier to get Android device is that it is made by Apple.
The only counter argument would be investement in ecosystems. Assuming you've invested hundreds, or thousands into iOS applications. BUT, if thats the case, again, all that means is Apple has you locked in and as such can charge whatever they want.
The freedom for the consumer has never been more large, the choice made is made through emotional needs, not rational ones.