Currency is a generally accepted form of payment, usually regulated by governments. Fiat money, or normal currency, even has exchange markets and fluctuations relative to other currencies. It’s just paper.

When considering crypto currency ,there are multiple digital currencies and they fluctuate. So this is considered a market and valuable.

Bitcoin actually made the adoption rate faster. Meaning there are countries which have adopted bitcoin and are very open to Bitcoin. Bitcoin is a digital asset and scarce as well, which makes it more valuable than other digital assets. With convenience and decentralised functionality Bitcoin eases international trades.