#1) it doesn't pay any dividends like stocks
#2) risk of extended drawdowns which could cause loss of principal unlike in a real estate investment where the property only goes up in value
#3) unfavorable tax treatment since it cannot be depreciated like many types of assets can be when used for business purposes
the fact that it doesn't pay any type of periodic cash flow while it is owned is a serious issue. for these reasons i don't really like bitcoin as an investment.
1. It doesn't pay dividends but it appreciates a lot quicker than stocks even with their dividends included. Also not all stocks even pay dividends.
2. ummmm I'm not sure where you got the idea that real estate only goes up in value lol, you must be quite young and inexperienced if you think that. And you are supposed to be listing downsides of HODLing, but a temporary crash in Bitcoin price doesn't effect long term holders at all (other than allowing them to buy more).
3. Bitcoin doesn't have "unfavorable tax treatment". Not sure where you got that idea. It is taxed the exact same as other assets. You sell it: you pay capital gains taxes.