Not that hard to believe when you consider the hardware specs for Apple machines are so heavily locked down to a very specific set of mobo, cpu, and only variability in core count, ram amount, hard drive size, etc.
It's not like PC world of mix and match everything.
It's hard to believe because virtually none of the proprietary Apple Silicon platform (except the CPU instruction set itself) is documented and involved a tremendous amount of reverse-engineering effort by some very bright volunteers.
Agreed, if anyone wants some good insight, this video is fantastic. It gets to the tech stuff about 20 mins in iirc and explains some quite surprisingly open aspects of the apple ecosystem and some approaches to funky stuff with the closed bits.
It's an appealing platform. Entry level is $600, nice memory systems (66GB/sec to 800GB/sec), and nice iGPU. The laptops have nice keyboards, nice trackpads, nice screens, and great battery life. The desktops are built in a solid aluminum chassis and have a single fan (instead of the normal 4-8) and are small and quiet.
I do wish apple did a native apple port, but the community is making good progress on that front.
Marcan, Asahi Lina, and related folks have been working on improving 3d accelerations. It's good enough for desktop use and some gaming so far, games like tuxracer, video playback, minecraft, etc. First the driver was in user space in python, then in the kernel with rust, and recent improvements have increased parallelism (from Lina) and removing Mailboxes (from Marcan).
OpenGL and Vulkan compliance has been increasing. Last I heard OpenGL was at 99-100% (almost all tests passing) and Vulkan wasn't as good, but improving. I believe Alyssa Rosen is doing much of that work.
There are some posts on Twitter and/or Mastodon, and regular updates on YouTube from "Asahi Lina" and Marcan, often by Live stream and Patreon.
Oh, and Neal Gompa is working on getting the GPU working with Fedora. One problem is most ARM linux distros default to 4k pages. But the GPU (which shares memory with the CPU) requires 16k pages. Seems like a performance win (less TLB thrashing), with a marginal increase in memory use.
Vast majority of hardware used by the open source community is proprietary and undocumented, and always has been. They embrace the challenge of reverse-engineering.
I hope I get to be a badass challenge-embracing reverse engineer like the people behind Asahi one day. I've done some USB stuff but have no idea how they're tackling all the other hardware.
GNU / Linux and BSD would never have started with that attitude. Most hardware was proprietary back in the day, and still is proprietary today. Even Thinkpads (a favourite among BSD devs) have proprietary subsystems that are reverse engineered. The alternative would have been to sulk and whine about it and do nothing. The hardware vendors truly do not give a f**k. They are run by business people, not open source idealists.
Your italics are strange and makes me wonder if you are trying to convey something. My first thought is that if the reverse engineering was done anonymously or pseudonymously, then the ones best positioned to do it would be actual Apple engineers who have insider information and feel like sharing with the world.
It's not like PC world of mix and match everything.