The biggest feature of iPadOS 16 will only run on the M1 iPads. Apple has now explained in more detail why this is the case.
iPadOS 16, unveiled at WWDC 2022, brings floating windows to the iPad for the first time with Stage Manager. The optimized multitasking interface groups multiple apps and their windows together and allows users to switch between them seamlessly. However, the Stage Manager feature is exclusive to iPad models with an M1 chip. So while many iPad devices are compatible with iPadOS 16, some of them will not be able to enjoy floating windows. The only iPads that will benefit from Stage Manager's new multitasking interface are those with a chip that was built into the first Apple Silicon Macs. Apple has provided an explanation for why this limitation exists.
iPadOS 16: Stage Manager needs new memory swapping feature
According to Apple, the Stage Manager requires the fast memory swapping feature in the new iPadOS. This allows apps to convert the hardware's free flash memory into temporary RAM of up to 16 GB.

This resource-intensive environment requires the power of the M1 processor, Apple said in a opinion to Digital Trends. Therefore, the iPad Pro 2021 and iPad Air 2022 are the only devices that can use the advanced multitasking interface in iPadOS 16. For over a decade, Apple has limited some features in operating system updates to newer hardware. For example, 4K ProRes recording is limited to the iPhone 13 models with 256 GB or more storage. iPadOS 16 will be available in Autumn be available for all supported iPads – You can find more about device support here. (Image: Apple)