[bluecat22]

Because in the space of open source operating systems, we realistically only have Linux Kernel.

With each new release of Linux kernel, the internal kernel interfaces that device drivers use, change. So whatever binary kernel driver the vendor released with kernel version x is not going to run with next kernel version y.

You only have 2 options: 1. Either you get the source of device drivers, which the vendors don't release because they want to protect their hardware IP

2. or the kernel keeps its interfaces stable so that drivers released can be reused again.

Right now, both are not happening and that is the real reason Android phones have a life of at most 2 years.