I was on a regular 3-year upgrade cycle since my 3GS purchase in 2009. From there it was the 5, 6S, XS and my current 13 Pro. A three year gap in between upgrades until the 13 Pro, which is in its fifth year (one battery swap). I might be ready to jump ship for the 18 or 19 maybe Pro maybe not. After 5 years this phone does not present to me as long in the tooth, although I’ve not held the current model.