Emergency fund

So in the traditional finance, they always say that you should have an emergency fund at least 6 months of your salary just in case. now that we have Bitcoin I don't think this makes since anymore why keep 6 month of cash when I can put this cash in Bitcoin and in case if difficult times come I can simply sell my Bitcoin and use the cash and that time

that time may or may not come so why prepare for something that has 50% probability of happening what I am thinking of doing is keeping just enough to meet minor unforeseen expenditures and in case there is need for funds then I can use my Bitcoin that time.