> In contrast, the ARM world sucks hardcore - there are no standards for board bringup and boundaries

There are standards for ARM, and they are called UEFI, ACPI, and SMBIOS. ARM the company is now pushing hard for their adoption in non-embedded aarch64 world - see ARM SBBR, SBSA, and PC-BSA specs.

Yes but these standards are clearly far from enough to run Linux on M chips otherwise the support wouldn't lag so far behind.

> There are standards for ARM, and they are called UEFI, ACPI, and SMBIOS.

The most popular ARM dev and production board - the Raspberry Pi - doesn't speak a single one of these on its own, so do many of the various clones/alternatives, and many phones don't either, it's LK/aboot, Samsung and MTK have their proprietary bootloaders, and at least in the early days I've come across u-boot as well (edit: MTK's second-stage seems to be an u-boot fork). And Apple of course has been doing their own stuff with iBoot ever since the iPhone/iPod Touch that is now used across the board (replacing EFI which was used in the Intel era), and obviously there was a custom bootloader on the legacy iPods but my days hacking these are long since gone.

I haven't had the misfortune of having to deal with ARM Windows machines, maybe the situation looks better there but that's Qualcomm crap and I'm not touching that.

They should have pushed for it years ago, ARM's devicetree clutter and bootloader "diversity" has been a curse on the end user. At this point it's too late, and doubtful that they even have the influence to make OEMs adopt it.