> Also, the CPU is but a minor part of the puzzle. But still that is still twice as many as apple (good luck exchanging that apple-arm with any other brand).

Even on x86, interchangeable CPUs are the exception, not the rule. Intel and AMD CPUs haven't even used the same socket since the 1990s, and even within those manufacturers, socket incompatibilities are common.

Software interchangeability is more of an operating systems issue than an architectural one. With appropriate software shims, though, there is no reason to suspect that (for example) Linux ARM software could be run on an Apple ARM CPU. In fact, it's quite likely that tools like the Android emulator will do exactly that.

> Please compare that with a computer built from AMD/Intel with a motherboard out of dozens of manufacturers etc. Any ATX power supply etc. Pretty much any PCI-E graphics card etc.

Server-class ARM hardware generally does use similar parts as x86 servers, including power supplies and PCIe peripherals.