I agree with your comment, but I want to add the answer to "Why couldn't a mobile phone work for 15years?": because the evolution of chips and software makes a

I agree with your comment, but I want to add the answer to "Why couldn't a mobile phone work for 15years?": because the evolution of chips and software makes a new phone much more efficient (energy, user's time) than a 10-15 years old one. I used a Samsung S3 as a GPS-only device on the car dashboard for a few years after I was no longer able to use it as a smartphone (old Android with no updates), getting a new smartphone was required not because the old one was "old", but because it was obsolete enough to be unusable.