Its all of these things you mentioned!
-Its a currency as it could be traded and exchanged.
-It is a security ,same way as the stock is.
-Bitcoin is a commodity as it could be exchanged with other cryptos using atomic swaps.
Sad thing is to be currency not much country that allow it as payment, but you right, bitcoin already can called all that thing because it is almost like fiat money, only need to be more adopted.