Not quite true. My grandfather was a carpenter specialised on furniture and windows. He would say everything off 0.1 mm or more is that bad that you have to redo the piece. And he was right: A 0.1 mm gap in a joint is an ugly and very visible gash in your work.
If the error is less than 0.1 mm it is still not good work, but you can hide it with glue and sawdust. It is still rather easy to detect if you run your fingernail over it, but at least it is not that visible anymore.
He used big machines and hand tools, but no milling, CNC or other computer controlled machines. So decimals in millimetres are definitely useful outside of milling and the precision is achievable - even for me, who isnt a professional woodworker.
My guess is that most ppl who put bread in the fridge buy that sliced rectangular stuff in a plastic bag (at least my flatmate did that). Bread from a bakery, which has a crunchy crust should not be put in the fridge, as others have pointed out.