For audio, yes, digital can replicate analog to 100% accuracy. You cannot differentiate the output signal using an oscilloscope. The signals are identical. People using workflows you describe are a cult, IMO.
I think this is true, but definitely not in real-time. Go observe how fast a complicated analog SPICE emulation is. Typically it's about 1000x slower or worse than real-time, though in the end the wave form might exactly match the actual circuit.