Both are good. Which is better? A house or food? They just invest in different asset classes. Bitcoin has way better return currently but much more volatility. If that was all your wealth and it drops back to $3000 overnight erasing a quarter of your net worth overnight you may not be comfortable.
Its a good question though and the fact that you are thinking it and asking for other's opinions means you are prepared to challenge conventional wisdom and look for the best answers. But then I guess that's why you are the sort of person to have found Steemit. :)