Maybe we’re not taking about the same thing. You’re saying there’s PPC code running on current macOS. If it’s running on recent hardware, it’s running emulated, since Apple hasn’t shipped a PPC machine in more than a decade.

I’m saying the exact opposite: that there’s likely PPC source code in macOS still maintained just in case. I really doubt all of the Carbon remnants are ISA specific, the point of bringing that up was that macOS’s roots are not entirely NeXT and things that still exist are based on APIs largely from classic Mac OS.

I really doubt they are maintaining a PPC fork. It's not a trivial effort and it would be hard to justify the investment and even harder to motivate the talent needed.

ISA specific code is restricted to kernel and drivers. What's left of Carbon has been through 3 transitions (PPC to x86, x86 to x64 only, x64 to ARM). It's ISA clean all right.