Apple is a victim of their own success. Their products are so good....people are in no hurry to upgrade from the Apple products they bought several years ago. They are still “good enough.”
Of course, that assumes I stay with the phone. I rarely use my phone as a phone, but more as a mobile computer that occasionally makes/takes calls. I might switch to an iPad with cellular data and use some form of VOIP for my limited "phone" use, depending on the service plans my wife an I can work out with one of the major carriers.
I just cranked up 2005 model of Mac Mini G4 processor to run HyperCard and AppleWorks 5.0, bought it on eBay for $95.00, similar systems still sell for up to $200.00, or about the price of a new commodity PC.