Bitcoin has many similarities to gold. But societies have persistently chosen to use fiat currencies over gold.
I LOVE how you portray this as a positive thing when it's really the start of where all the fraud began.
Y'all may not have noticed this, but local rhetoric aside where 'fiat' is always short for 'government fiat', from an economist's perspective, or a literalist's, Bitcoin is absolutely a fiat currency.
A fiat currency is defined by the fact that there is no one promising to exchange it for a fixed quantity of some valued object or service as a way of guaranteeing its value. Nobody's offering to give you a beer (or whatever) per bitcoin even if the bitcoin price drops below the price of a beer (or whatever), and that makes Bitcoin a fiat currency.