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.

Constant rise in bitcoins price is not important because we need the volatility of the market in order to earn more profit since everyone is not wealthy enough to invest on bitcoins with a very expensive price.