Linux

Because the driver is the glue code between the device, and the operating system. What happens when the kernel changes, or needs to change? Then the driver on your devices don't match up with the kernel anymore. A lot of Windows folks think Windows has some sort of stable interface and that's why Windows is backwards compatible. But it's untrue, Windows has inbox drivers, just like Linux has driver's that build with the Kernel. Any driver that reaches inbox status get brought into the Windows source. As the Windows kernel changes, Microsoft engineers update all the inbox drivers to match the new kernel changes. When companies don't get their driver inbox'd, they are responsible for keeping up with the kernel changes. Some devices eventually get left behind.

Because there is no such thing as a universal standard for software.

You're imagining a way for software to talk to each other with something like Esperanto, right? Some universal library interface, a language that can be compiled for every CPU architecture, byte ordering, and operating system.

This would require all hardware vendors to agree on what that interface is, for each type of device. It would require that the API never changes, or else old devices wouldn't work with new OSes; the alternative is that OSes have to support years of different versions of the language. It would prevent bug fixes, unless you add the ability to flash individual chips, which would make many more expensive. It would have to be a higher level interface which would limit both innovation and performance tuning. But the biggest issue is that this universal language would have to understand every operating system to know how to access itself using the OS's paradigm.

Unfortunately, If they did have onboard drivers it would only ever be for an old version of Windows. (Same as the disks and then later discs that used to come with hardware)

And in the case of phone hardware and features such as VoLTE it's intentional so you're locked into their OS.