But you may be the leading edge of what could easily become a "key demographic": people who don't upgrade for many years. It's possible that "things I could do with a new phone that I can't with my existing phone" will be worth less than the cost of a new phone for an increasing number of people. Or not. I don't think anyone knows for sure how that will evolve over the next decade or so.
My smartphone's getting on for 9 years old; I don't think I'm a key demographic ;)