You can definitely live with a voice-only phone, though the current models are horrible (I miss the real Nokia phones).
If you want to live luxuriously, also put a netbook, X1 Carbon, MacBook Air, whatever, in your backpack, then you have Internet, too.
This is not an excuse for the outrageous tracking plans of Apple and Google, I just hope more people will do this as a reaction to those plans.
EDIT: I may have misunderstood the "no alternative", I assumed it was about the need to own a "smart" phone.