Yes, I agree an AMD chip isn't an Intel emulator. However, if we were imagining an intel CPU inside a console like a Super Nintendo or Megadrive, then an "AMD

Yes, I agree an AMD chip isn't an Intel emulator. However, if we were imagining an intel CPU inside a console like a Super Nintendo or Megadrive, then an "AMD CPU" wouldn't be good enough -- lots of games require bug compatability of undocumented instructions, and exact behaviour in terms of memory access, instruction execution (including how partial instruction execution effects memory + registers). People at Analogue aren't just making something which implements the same instruction set, they have to implement exact behaviour in all ways. Nowadays people don't write games which require that level of compatability, which is why (mostly) games work on both Intel + AMD.