In a capitalist POV, redundancy is just unneeded cost for things that are “not needed”.

In an engineering POV redundancy is insurance to make sure things work as needed even when part of the system fails.

For example, Apollo flight computers were triple redundant, and the outputs from all three were compared before being fed into engines. If two outputs would be 0.98, but one was 0.12, it’s most likely that the third one is wrong and should be discarded. This makes it very likely that correct control intput is given to the engines all times and the whole thing would not crash and burn because of a random bit flip.