It is infinitely more than the number of iPhone apps that have not recieved updates in 6-8 years that are still runnable. Even mac apps will often have trouble in that kind of time frame.
You're also the one who expected "all" to work cross gen. My original point was just that "all" would work on the software for a given piece of hardware that worked on the original hardware. The fact that 99.9% also work on the next gen is a bonus, because the same gen compatibility already leaves Apple's backwards compatible story in the sand.
You're also the one who expected "all" to work cross gen. My original point was just that "all" would work on the software for a given piece of hardware that worked on the original hardware. The fact that 99.9% also work on the next gen is a bonus, because the same gen compatibility already leaves Apple's backwards compatible story in the sand.