I use Apple’s iPhone Upgrade Program to get Apple’s latest and greatest iPhone every year. I justify this a few ways:
1. The cost of the phone is essentially halved because I’m paying for the cost of phone divided over 24 months, and when trading it in after 12 months it stops payments on that device. If I were to buy the phone outright and then sell it after a year, I might get slightly more than 50% the cost of the phone but you also have to factor in all the effort needed to list it, sell it, ensure payment is delivered, or meet the person you are selling it to and hope they pay/won’t stab you.
2. I use my iPhone literally every day. In terms of spending money on something that seems excessive, I do not put iPhones in such a category. I take pictures with my phone every day. I listen to music, use apps, surf the web, check personal and work emails, and do other personal and professional work on my phone every day. I watch movies, tv shows, and often play games on my phone each and every day. The phones can cost $1000+ but I use this device more than I even drive my car. Think about a semi big ticket item you’ve purchased in the last 5 years and ask yourself how often do you use it? Chances are that some of those items cost far more than an iPhone and are used WAY less.
Due to those reasons I feel it’s useful to have the latest and greatest device. It’s worth while to me and I can afford it. Now this obviously isn't the case for everyone but I feel as long as most people replace their phone every 2-3 years then they are getting even greater value out of them, despite not having the most advanced features.
IMO holding onto a phone more than 3 years is silly and anything after 5-6 years is foolish, because:
1. The battery may be diminished enough to make charging more of a requirement throughout the day.
2. Certain features/app may not work or not work as well, especially on 5+ year old devices.
3. If the device is having issues, which is almost a guarantee after enough time has passed, what is your time worth having to go get it serviced time and again rather than just purchasing a new one.
Buying a new phone each year on the upgrade plan eliminates most of these annoyances, makes it easy to return the old device, allows me to only pay for the time I use the phone, and allows me to keep using the newest tech with a brand new battery and not have to worry about issues. To each their own but those are my reasons for upgrading each year.