It's simple, really: Newer devices are faster and have nicer features (e.g. better camera) and it's not really that inconvenient to pay an extra $20-30/month t

It's simple, really: Newer devices are faster and have nicer features (e.g. better camera) and it's not really that inconvenient to pay an extra $20-30/month to get a new phone every two years. You can pay $150 to get a new battery put into your old phone but that doesn't seem worth it when you can get an entirely new phone that's "better" than your old one for $500. If it were cheaper and easier to replace old batteries I'm guessing that people would keep their old phones much longer. That's my #1 reason for buying new phones: The battery in the old one just doesn't last as long as it used to and replacement batteries can be hard to come by and/or they're a serious pain to install (high risk too!). Within the next two to three years though (assuming the global chip shortage lets up) we should start seeing phones with carbon cathode technology. Then again, car manufacturers might hog all the dual carbon and carbon cathode batteries so it might take a bit longer.