> I’m not that interested in hacking on the instruction set it runs on. This makes zero sense, frankly. Do you also feel this way about an x86 laptop, that x86

> I’m not that interested in hacking on the instruction set it runs on. This makes zero sense, frankly. Do you also feel this way about an x86 laptop, that x86 isn't worth learning anything about? Because it might run macOS? It's pointless. The main thing tied to the OS is the userspace ABI (e.g. callee/caller saved registers, parameter passing), but this is generally only one important-but-small part of actually using the CPU, or doing low-level optimization, and every major operating system (including macOS!) tends to have quite detailed ABI documentation for all the supported architectures. Actual fundamentals of the ISA, the supported instructions, etc all translate between operating systems cleanly, and for a given microarchitecture the performance characteristics will also broadly translate between operating systems. But I sort of doubt you're talking about low-level Apple Silicon-specific uarch optimizations, because that's not what the original guide is talking about. Like, if you don't already know how to write ARMv8 assembly, macOS is not what's stopping you. You can take most of this knowledge, which is fundamentally generic, and just as easily apply it to an RPi for example, or the new Snapdragon X Elite, etc. macOS is mostly a non-issue in this regard, it just happens to be the operating system "of choice" for some of the best client-oriented ARM processors you can buy right now.