We should think more about the risk of having all your investments in one single portfolio, such as bitcoin. Bitcoin happens to be the most reliable cryptocurrency for investment but at the same time, Bitcoin is a highly volatile asset. So I will still advise you to diversify your portfolio into multiple sources.
I agree. It is not uncommon on a bitcoin forum to have people who have either all in bitcoin or a very significant part of their net worth in it. I prefer to be diversified.
The problem with having it all in bitcoin as the OP comments is that some people panic when things don't go as expected and sell at a loss.