Yeah bingo. A barter based economy would only work with a tiny number of participants. Say an island with 100 families. Any larger and it becomes so inefficient it would likely collapse.I think the keyword here is standardisation, right?
Alot easier to say a chicken is worth $10, than say it's worth 20 bananas OR 15 carrots OR 5 old school Cadbury Chocolate bars.
Further to that, fiats value is more controllable. Goods are subject to rareity (seasonal, supply etc) and quality degredation (expiry dates).
I like Bitcoin and all that, but all it is is basically a digital gold rush. Whoever gets in first, profits the most; given a sustained/increased demand.