Certain applications are unavailable for installation or use on iPad devices operating with iOS 9.3.5 due to the software requirements of the application exceeding the capabilities of the older operating system. As an illustration, a newly released photo editing suite demanding iOS 12 or higher cannot function on an iPad locked to the 9.3.5 version.
This incompatibility stems from the ongoing evolution of software and hardware. Developers often leverage newer operating system features to enhance application functionality and security. Older devices, constrained by their processing power and memory, cannot support these advancements. This situation highlights the trade-off between maintaining older devices and accessing the latest software innovations, affecting user experience and potentially limiting access to current services.