The issue is societal lockin - aka network effects. People can't afford to "not buy one" because then they are "the one without".

Banking apps, delivery apps, public transport apps, utilities apps, insurance - so many services have been captured by the big two phone oligopoly that modern life revolves around your phone. The assumption is that you will have one.

Sure, you could decide not to, but you are instantly a societal pariah as every business finds it s so much harder to deal with you - and you don't have enough time in the day to deal with the secondary processes these businesses employ, for every aspect of your life.