... but holding Dollars now seem very risky...
Bro, over the past year the dollar has lost less buying power than BTC has over the past 24hrs. Learn life.
Keeping Dollar instead of Bitcoin was a good trade this year but long term I don't think it will. Rich people have their wealth in assets not fiat.
You need to look at a much longer time frame then just one year when determining how good of an investment something is/was. Looking at a one year ROI is an arbitrary short time frame. If you were to double that and look at a 2 year ROI you will see that someone who purchased bitcoin this time in 2012 would have grown their money by ~30x while the value of their dollar would have been roughly the same (there was very low inflation over the past 2 years)