You don't have to be phone-addicted for your phone usage to keep going up. In a lot of societies ever more daily tasks continue to migrate off PC and onto phone apps. The number of services you interact with primarily through your phone (say, booking a hairdresser appointment or getting notified your dry-cleaning is done) keep going up everywhere. People use their phone for contactless NFC payments, for public transit check-in/check-out, etc. Having enough charge to last the day becomes increasingly not optional.

Everyone gets habituated by context to look at the thing more and more as the gateway to everything.