Yes as long you use a thing to pay it is called money, so Bitcoin and other cryptocurrecy is a money that thing that it is different with the fiat is it's appearance because bitcoin is a digital currency. So bitcoin is a money and the other alt coin too.
I do not agree with what you say, bitcoin is not an altcoin, it is a core coin, it is the foundation of all the other altcoins. It's like a common currency of technology, it has the same power and power as cash. Bitcoin is a digital coin that represents the evolution of technology, it is even stronger than many of the current cash in the world.