Not mandatory, but I'd say a very desired feature. I myself have been into situations when I'd sell my crypto because I needed money, even though that was extremely unprofitable, plus the fees were high. I knew that wasn't time to sell and I wouldn't have done so if I was financially secured otherwise.

I've learned my lesson and now I only buy when I'm confident that in the nearest future I won't need that money and won't have to sell.

Nevertheless, one can make a profit from short-term returns with alts, or daily trading, I don't think financial stability plays such a big role in these cases.