One big issue with Linux is driver maintenance. If a distro can focus on just one set of hardware (e.g. M1 Macs), it allows the developers to optimize the distro massively. It also makes everything more predictable, and saves a lot of time.
Not to mention that the M1 macbooks have outstanding displays, speakers, mics, etc. Imagine a world where the distro has perfect drivers out of the box, and we don't need to use some subpar nouveau driver (when I say subpar, I'm speaking relative to the official drivers).
Not to mention that most people run Linux on crappy $1000 laptops. An M1 air is around that price range, and destroys anything in that particular market space.
This could be massive for Linux desktops. I feel like the one thing that has been holding it back has been this very issue. It even opens up the door to reverse engineering the Apple hardware and perhaps creating a complete open source integrated system in the future.
It matters, and it could be the thing that rocket blasts Linux into more normies homes.