I think the explanation for why we don't observe macroscopic quantum phenomena is rather more simple than that, and likely has more to do with the results of a

I think the explanation for why we don't observe macroscopic quantum phenomena is rather more simple than that, and likely has more to do with the results of a superposition of a large ensemble of possible states than some fairly strained analogy with computation (think of it as something like fourier decomposition of a function).