Not sure what you mean wrt to Apple's uniqueness. AMD/Mediatek/Intel/Qualcomm/Samsung only make margin on how well they invest on their designs vs their competitors and they'd all love to be outshipping each other and Apple in any market. All, including Apple, also rely on the same manufacturer for their top products and the ones (Intel/Samsung) with alternatives have not been able to use that as an advantage for top performing products. Sure, Apple can work directly with their own product... but at the end of the day the goal and available customer pool to fight over is the same and they still ship fewer units than the others.
I'm not hands-on familiar with other serious ARM server market players but for several years now Ampere ARM server CPUs at least are nothing like you describe. Phoronix says it best in https://www.phoronix.com/review/linux-os-ampereone
> All the Linux distributions I attempted worked out effortlessly on this Supermicro AmpereOne server. Like with Ampere Altra and Ampere eMAG before that, it's a seamless AArch64 Linux experience. Thanks to supporting open standards like UEFI, Arm SBSA/SBBR and ACPI and not having to rely on DeviceTrees or other nuisances, installing an AArch64 Linux distribution on Ampere hardware is as easy as in the x86_64 space.
Ampere is a bright spot in all of this, indeed. Just considerably late. I remember being bombarded by "ARM servers are going to eat the world" in 2013, but ARM couldn't deliver SBSA in shape that would make it possible and to this day I am left with serious doubts if any ARM board will work out right (there are bright spots though).
As for Apple "uniqueness", I met a lot of people who think that Apple "just" has so much better design team, when it's similar to what you say and the unique part is them being able to properly narrow their design space instead of chasing cost-conscious manufacturers.
I'm not hands-on familiar with other serious ARM server market players but for several years now Ampere ARM server CPUs at least are nothing like you describe. Phoronix says it best in https://www.phoronix.com/review/linux-os-ampereone
> All the Linux distributions I attempted worked out effortlessly on this Supermicro AmpereOne server. Like with Ampere Altra and Ampere eMAG before that, it's a seamless AArch64 Linux experience. Thanks to supporting open standards like UEFI, Arm SBSA/SBBR and ACPI and not having to rely on DeviceTrees or other nuisances, installing an AArch64 Linux distribution on Ampere hardware is as easy as in the x86_64 space.