If it is not currency then why does people accept it as mode of payment? Even countries like El Salvador, Brazil and many more accept it as a mode of payment. You can deny it as long as you want but the proof of Bitcoin being a currency is evidently strong.
almost any large business that accepts bitcoin immediately converts it to fiat .
el salvador is a country with failing economy , they embraced bitcoin as a hopeless way to get rich .same way they did with the us dollar more then 20 years ago .
so far it didn't help .