For the software to perform beamforming it must be provided the discrete microphone inputs, as opposed to being provided some sort of pre-mixed feed. As such, why is Apple "trying way too hard to be fancy here" if you can just use one of those mics? Or is the alternative that they do the "beamforming" in hardware regardless of the OS?
> if you can just use one of those mics?
They're extremely omnidirectional and very sensitive. With a single mic with no beamforming you get basically all of the sounds from every part of the room, including and especially horribly loud sounds from (eg.) the keyboard and mouse.
Apple selected their microphones based on the constraints their system had (beam formed array) rather than the "usual" laptop microphone which is physically not very sensitive and highly directional towards the front of the laptop, and in turn, those microphones are not particularly useful without beam forming.
Other laptops with beamformed arrays simply don't expose the raw mics to userland, by doing the beamforming in firmware, but this of course comes with its own set of issues.
> Other laptops with beamformed arrays simply don't expose the raw mics to userland
Not always true, back in the Windows XP days (!!!) some laptops would expose the array to software and let the user configure where the mics record from.
It is unfortunate that user control has been polished out of modern systems in exchange for "it just kind of works".
Avoiding extra coprocessor and/or avoiding patent dispute like they did with speakers (which differ from a H-K patent by not having a discrete chip implementing it)