I have the impression that you and your friends experience cryptocurrencies as a company. Now that it's in decline, you can't live on it. someone who does programming or development in the crypto industry and is paid for that work in cryptocurrency does not have the same problem as you.
although I would rather say that you did not formulate the advice well.
I assume that you meant trading in cryptocurrencies (which is only part of the possibilities that crypto offers). even though it is now a bear market, it is still possible to make money by trading. although in a bull market everything is much simpler.
yes, you are right, your friends should not have quit their regular jobs, not because they are dealing with cryptocurrencies, but because they are not good enough to be traders.
you don't become a dentist just because you know how to brush your teeth.