Says it's a perfectly functioning phone and then lists how it's not because it's old and got worn out. apps requiring later versions is an issue but the % of people on old iOS versions is really quite small. It makes no sense to waste development time on implementing something for <1% of customers on iOS 14, when you could use a newer API in one line of code.
It’s not just apps requiring later versions, it’s apps using more and more memory due to the use of ever-more bloated frameworks and the like.
The vast majority of these apps would’ve run fine on a computer from the 1980’s running at a handful of MHz in mere kilobytes of RAM, if they were optimized. But they use the trendiest frameworks and require gigabytes of RAM and gigahertz of clock cycles to run their todo-list (or whatever it is they do).
Apps don't support older OS versions -> Nobody uses old OS -> No point supporting old OS as nobody uses those -> Apps don't support older OS versions -> ...
