Most computers have been like that, FOSS got lucky that IBM failed to secure the PC for themselves, thus the PC clones.

When folks say Intel and AMD are done, and we should all be on ARM, or RISC-V, beware of what to wish for.

Yes there are device trees now, however someone has to keep them up to date, and that is only part of what makes a motherboard.

Other than this situation, what other landmines are there? I have an M1 with Asahi Arch Linux that I've been using as my primary laptop for the last 8 months, its my favorite laptop by far out of the 5ish I have.

Pretty much all ARM platforms are. Even ARM devices designed from the ground up to be Linux devices are full of issues, like the MNT Pocket Reform's lack of HW suspend. The tight interop between vendor and implementation is a huge anti-pattern for software freedom, and the standardization initiatives like ARM SR are nowhere to be seen. It's probably the most problematic part of ARM being the future of personal computing, yet another impending manifestation of enshittification.

i run linux on both in arch and fedora versions with zero problems, by using the hypervisor framework of macos and wsl2 (wrapper for hyperv). do you need a more direct than hypervisor access to some hardware?

what about the ones from CIX like the orangepi or their framework mainboard? (though I agree, I miss UEFI for all its faults)