> Microsoft knew that, so they made sure to be ABI compatible so they could keep updating the OS.

I don't remember it that way. I remember buying motherboards and receiving CDs full of drivers for the many Windows versions. I remember having to scour the internet for drivers and finding a different one for each Windows version. I remember failing to find drivers for new versions of Windows because the manufacturer couldn't care less. I remember incredibly shitty manufacturer applications that took over one minute to display a window on the screen. I even managed to reverse engineer one of those into a free software user space driver.