Also, if you 1 one bitcoin you can only sell less than 1 bitcoin from transaction fees. Remember, someone needs to spend real money maintain servers and that money is constantly being removed from the coin ecosystem.
If I own a house I get to use the house today and still have a house tomorrow. With a field I could grow crops and then still have a field next year.
Commodities are an interesting 3rd thing. But, closer to buying something from a wholesaler than an investment as they represent actual goods (ie Oil) that will be sent somewhere. Think of it like this, if you buy coffee contract you get coffee which can be sold off. However it's a physical thing and it's got a physical expiration date, if you keep it in a pile somewhere for 10 years you end up with dirt.
You could speculate that the utility created will increase the value of the coins you hold. However, unlike mining there is no connection between buying a coin and enabling other people to do these transactions.
However, over a long enough timeframe storage fees eat up the entire value of gold stored thus it's not a long term investment.