I think if you are not sure about bitcoin, you'd better keep it in fiat money
because bitcoin is very volatile. you should be ready with all the possibilities that exist, including losses
1 BTC could be down cost only $ 100, it may be due to fluctuations
so you should know the risks
I agree, safe if not just about the physical security of bitcoin, like the wallet providers, but also include the volatility of bitcoin. If a currency is really volatile that it goes through hyperinflation, it is not safe as well. Bitcoin has reached a steady price, with some fluctuation, but still, better to keep most of your money in fiat and treat bitcoin like an investment.
Let just put it this way. The chances of bitcoin prices going down is greater than the chances of fiat (stable currency) prices going down. Although bitcoin is not as 'safe' in terms of the price, I do agree with all the advantages, so I trust bitcoin to be safe too.