Simply because the WHALES take the profits whenever there's a 5 to 10 percent growth. The bottom line is Swing trading and Day trading is real and the HODL method is just what it is...
Day trading is more profitable than holding in the long run where patience is needed. But for bitcoin rising in the price of 20k it is not impossible, because it's just a matter of time and I believe bitcoin will be able to reach 20k.