Let's say you bought a bitcoin for $1000 in January 2018.
So you have to beat inflation and also the performance of other investments to say that your Bitcoin investment was a better investment, than other alternative investments.
Let's say your inflation is 5% and your best return on some other investment is %20 per year, then your Bitcoin price increase will have to be more than %25 to beat the alternative investment.
Let's say you hoard for 5 years, then you would need a price increase of 125% to beat your alternative investment returns over 5 years.
So we cannot have a price increase of 800% in year 1 and then a price decrease of %400 in year 2 and another price decrease of 200% in year 3 and so on...
Hope you get at what I am saying. Hoarding might be harmful to your profits, if you do not cash out SOME profit on the ATH.

..... You might end up with a bitcoin worth $100 in year 5.

There are many ways of investing and one is that buying the commodity when it is in a low price and sell it at the high price so when in case bitcoin end up having a low price in the year 5 then I would buy some bitcoins to make my average price per bitcoin low and when bitcoin come above my average price then I will sell some coins and live happily.