I tend to use mainly older hardware of known-repairable types, Thinkpads and HP business models. I've upgraded/replaced/repaired many of these systems using parts from just about anywhere ranging from whatever happened to be lying in the spare parts stack to vague eBay imports to 'genuine' spares. CCF tubes, inverters, CPUs, memory, drives, screens, keyboards, fans, coils, batteries, you name it. This has made it possible to extend the working life of said hardware far beyond the normal 'economical' life span - e.g. the machine I'm typing this message on is a T42p from 2004. This would not be possible with current Apple hardware which would instead be 'recycled'.
They still try and keep people from actually repairing their devices which are perfectly fine in many cases. So I believe it's still a valid point even if there could be better examples.
And honestly, you write
> updated for a long, long time
Are they really tho? A few years is not a long, long time in my opinion and even if you don't buy a new one for a couple of years and it's still updated they usually make it unbearable slow so that you cannot live with it anymore and purchase a new one. It is easy to update, but nearly impossible to go back to an older version if the new version turns out to be very slow.
My father still uses a dumphone and a windows phone. They both work surprisingly well for him, especially the windows phone. I am actually pretty amazed on the longevity of the Nokia Lumia.
Making a phone last 2-4 years is not a long time. I believe many people could easily have the same phones for 10+ years if the phone makers were interested of making that happen. They aren't though and that is a bit of an issue.
Just compare a phone to most other products and you will soon notice people update their smart phone a lot more often than most other things. Sure it's an important device but not that many people would actually need the feature upgrade every version have.
Make a phone that lasts 20 years or more and I will start to believe that you are making good, long lasting products.