And what the use of a noisy channel if it may changes bits sent over it? ;) You just need to have proper error correction. You are right - of course - if QM is

And what the use of a noisy channel if it may changes bits sent over it? ;) You just need to have proper error correction. You are right - of course - if QM is completely noisy, or you can't have proper error correction (due to some physical limitation for example). E.g. for quatum computation some people believes so: https://www.quantamagazine.org/gil-kalais-argument-against-quantum-computers-20180207/ https://www.quantamagazine.org/gil-kalais-argument-against-q...