Well i believe there are other more important and vital organs of the body that perform more better function than kidney could do since a damaged kidney could be replaced by another or sorrugated by an artificial one, when relating this same idealogy with bitcoin in cryptocurrency, it's more better to say than bitcoin is the head which constitute all the five sense organs and the brainbox of the whole body in which no other organ, cell or system could work without the head, bitcoin is the head of cryptocurrency and that settles it all.